Skip to main content
Home / Other Components / 21×12mm Plastic Knob Tube Amp Power Amplifier Audio Potentiometer Switch Cap Guitar Volume Control Round Knob

Attributes

Brand -
Category Electronic Components Market / Other Components
Origin -
Material High-quality ABS Plastic
Dimensions 21mm Diameter x 12mm Height
Shaft Fit 6mm Split Shaft (Standard)
Color Matte Black
Shape Round Dome Style
Compatibility Electric Guitar, Bass, Tube Amps
Package Quantity 2 Pieces per Pack
Weight 8 grams (pair)
Finish Non-slip Textured Surface
Installation Push-on Fit (No Screws Required)

6 reviews

A

Anonymous

Mar 29, 2026

Rating: 5/5

Exactly as described

The dimensions are accurate. They slide right onto the 6mm shaft and stay put. Very happy with this purchase for my DIY pedal project.

A

Anonymous

Mar 24, 2026

Rating: 4/5

Good value for the price

Bought these to replace some worn-out knobs on an old amp. They look great and function well. One knob was slightly loose, but a tiny bit of glue fixed it.

A

Anonymous

Mar 23, 2026

Rating: 3/5

Decent but basic

They do the job. The plastic feels a bit lightweight compared to metal knobs, but for the price, you can't complain. Good for backups.

A

Anonymous

Mar 17, 2026

Rating: 5/5

Great replacement parts

I needed specific size knobs for a vintage amplifier restoration. These 21x12mm caps were exactly what I needed. Fast shipping too.

A

Anonymous

Mar 09, 2026

Rating: 5/5

Perfect fit for my Stratocaster

These knobs fit perfectly on my guitar's volume pots. The black finish matches the hardware nicely, and they feel sturdy despite being plastic.

A

Anonymous

Mar 04, 2026

Rating: 5/5

Smooth operation

No scratching on the potentiometer shafts. The inner grip is strong enough to turn the pot without slipping. Highly recommend for guitarists.

5 FAQ

Q: What is the exact height of the knob?

A: The total height from the base to the top of the dome is 12mm, as specified in the product title and attributes.

Q: Will these fit a CTS potentiometer?

A: Yes, these knobs are designed for standard 6mm split shafts, which includes most CTS pots used in guitars and amps.

Q: Are these sold individually or in pairs?

A: This listing is for a pack of 2 knobs. If you need more, please adjust the quantity at checkout.

Q: Do these come in white?

A: Currently, this specific model is only available in Matte Black. Please check our store for other color options in different listings.

Q: Can I use these on a solid shaft pot?

A: These are specifically designed for split (slotted) shafts. They may not grip securely on solid shafts without modification or adhesive.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
Premium Ceramic Tea Canister and Gift Box Set - Empty Packaging for Black Tea, Pu'er, White Tea, and Biluochun

Premium Ceramic Tea Canister and Gift Box Set - Empty Packaging for Black Tea, Pu'er, White Tea, and Biluochun

$121.00

Posture-Correcting Hole-Grip Pencils for Grade 1 - Triangular Barrel, Break-Resistant, Non-Toxic HB for Daily Writing and 2B for Exams

Posture-Correcting Hole-Grip Pencils for Grade 1 - Triangular Barrel, Break-Resistant, Non-Toxic HB for Daily Writing and 2B for Exams

$3.02

Genuine OEM AC Blower Motor Heater Fan for Buick Excelle GT, Cavalier, and Monza

Genuine OEM AC Blower Motor Heater Fan for Buick Excelle GT, Cavalier, and Monza

$255.00

TA1 TA2 Titanium Capillary Tubes - Small Diameter Titanium Pipes - GR5 Titanium Alloy Tubes

TA1 TA2 Titanium Capillary Tubes - Small Diameter Titanium Pipes - GR5 Titanium Alloy Tubes

$240.00

Industrial Spray Painting Wipe Cloth Auto Bake Finish Film Application Degreasing Cloth Non-Woven Absorbent Paper Lint-Free Paper Electrostatic Dust Removal Paper

Industrial Spray Painting Wipe Cloth Auto Bake Finish Film Application Degreasing Cloth Non-Woven Absorbent Paper Lint-Free Paper Electrostatic Dust Removal Paper

$75.66

US Standard Buttress Thread Inserts 22ER 16ER 11NR 16 10 12 8ABUT Internal 7 External 45 Degree

US Standard Buttress Thread Inserts 22ER 16ER 11NR 16 10 12 8ABUT Internal 7 External 45 Degree

$43.20

Coating Workshop Cleaning Rags GAE Industry White Scrap Cloth Nylon Machine Cloth Blocks Industrial Glue Removal Furniture Cleaning

Coating Workshop Cleaning Rags GAE Industry White Scrap Cloth Nylon Machine Cloth Blocks Industrial Glue Removal Furniture Cleaning

$96.31

Natural 8A Yellow Tiger Eye Loose Beads - Round Cat's Eye Bracelet for DIY Jewelry Making

Natural 8A Yellow Tiger Eye Loose Beads - Round Cat's Eye Bracelet for DIY Jewelry Making

$17.28

Paper Blending Stumps Art Set for Highlighting, Sketching, and Smudging - Professional Drawing Tools for Artists and Beginners with Rice Paper Details and Oil Pastels

Paper Blending Stumps Art Set for Highlighting, Sketching, and Smudging - Professional Drawing Tools for Artists and Beginners with Rice Paper Details and Oil Pastels

$6.80

Rubber Speed Bump 1000x350x40mm Herringbone Pattern

Rubber Speed Bump 1000x350x40mm Herringbone Pattern

$96.89

Xian Kan Yun Shu [Cloud Lark] Elegant Brush Washer, Hand-Painted Orchid and Sparrow Design under Glaze, Ceramic Water Pot

Xian Kan Yun Shu [Cloud Lark] Elegant Brush Washer, Hand-Painted Orchid and Sparrow Design under Glaze, Ceramic Water Pot

$21.20

Cable Organizer Hook-and-Loop Straps for Data/Charging Cables, Laptop Power, Mouse, Headphones, and Under-Desk Network Wiring

Cable Organizer Hook-and-Loop Straps for Data/Charging Cables, Laptop Power, Mouse, Headphones, and Under-Desk Network Wiring

$7.48

Power Strip Organizer Box, Desktop Socket Concealment Case for Charging Cables and Power Cords, Hidden Storage Shelf

Power Strip Organizer Box, Desktop Socket Concealment Case for Charging Cables and Power Cords, Hidden Storage Shelf

$21.93

Automatic Dairy Beverage Filling Machine - Fully Automatic Equipment for Milk, Soy Milk, and Drink Bottling

Automatic Dairy Beverage Filling Machine - Fully Automatic Equipment for Milk, Soy Milk, and Drink Bottling

$1,316.00

Compact Invisible Retainer Case - Leak-Proof Sealed Storage Box for Children's Orthodontic Aligners

Compact Invisible Retainer Case - Leak-Proof Sealed Storage Box for Children's Orthodontic Aligners

$12.50

07521 Scouring Pad Roll for Woodworking, Furniture, Paint Sanding, Metal Deburring, and Brushed Finish - Purple 600 Grit

07521 Scouring Pad Roll for Woodworking, Furniture, Paint Sanding, Metal Deburring, and Brushed Finish - Purple 600 Grit

$81.00

Shiya Insulated Display Cabinet, Constant Temperature Warmer for Commercial Use, Crispy Pork Belly, Roast Duck, Roast Chicken, and Cooked Food

Shiya Insulated Display Cabinet, Constant Temperature Warmer for Commercial Use, Crispy Pork Belly, Roast Duck, Roast Chicken, and Cooked Food

$388.00

Wooden Soap Trimmer with Drawer, Soap Planer and Edge Shaper, Free Shipping

Wooden Soap Trimmer with Drawer, Soap Planer and Edge Shaper, Free Shipping

$32.00

Hell Training Rock Guitar by Shinichi Kobayashi Electric Guitar Textbook Tutorial Speed Picking

Hell Training Rock Guitar by Shinichi Kobayashi Electric Guitar Textbook Tutorial Speed Picking

$106.00

Zhao Mengfu Running-Cursive Calligraphy Copybook - Spring River in the Flower Moon Night Tang Poems for Tracing and Practice

Zhao Mengfu Running-Cursive Calligraphy Copybook - Spring River in the Flower Moon Night Tang Poems for Tracing and Practice

$16.00

Precision Transcription Service for David Tao's 'Small Town Girl' Saxophone Arrangement by Mr. Chui, Three-Piece Set

Precision Transcription Service for David Tao's 'Small Town Girl' Saxophone Arrangement by Mr. Chui, Three-Piece Set

$10.00

CANDLE.LAB | Small Wax Melting Pot 180ml with Stainless Steel Measuring Spoon for DIY Scented Candles 26

CANDLE.LAB | Small Wax Melting Pot 180ml with Stainless Steel Measuring Spoon for DIY Scented Candles 26

$16.00

Chengdu University City Laboratory Exhaust Piping and High-Purity Gas Pipeline Engineering - Consultation Welcome

Chengdu University City Laboratory Exhaust Piping and High-Purity Gas Pipeline Engineering - Consultation Welcome

$33,610.00

Premium Factory Supply Decorative Chains - Pendant Light Chains, Advertising Sign Hanging Chains, Anti-Static Iron Chains, Small Iron Links

Premium Factory Supply Decorative Chains - Pendant Light Chains, Advertising Sign Hanging Chains, Anti-Static Iron Chains, Small Iron Links

$61.15

[Damai Holds Micro-Needle Hair Transplant Patent] Precision Eyebrow Transplant – Custom Aesthetic Design

[Damai Holds Micro-Needle Hair Transplant Patent] Precision Eyebrow Transplant – Custom Aesthetic Design

$12,797.60

Commercial Dumpling & Bun Filling Machine – Automatic Stainless Steel Vegetable Chopper

Commercial Dumpling & Bun Filling Machine – Automatic Stainless Steel Vegetable Chopper

$4,400.00

HVAC Fan VFD Control Cabinet with Power Frequency to Variable Frequency Conversion

HVAC Fan VFD Control Cabinet with Power Frequency to Variable Frequency Conversion

$1,238.00

Export Quality Original Bathroom Paint Pens, Yellow and Green (2-Pack), Draw on Tiles and Glass

Export Quality Original Bathroom Paint Pens, Yellow and Green (2-Pack), Draw on Tiles and Glass

$4.93

Imported Automotive Transmission Differential Bearing B39-4 580704A

Imported Automotive Transmission Differential Bearing B39-4 580704A

$338.00

Fully Automatic Carbon Steel and Stainless Steel Filter, Self-Cleaning Vertical Filter, Automatic Blowdown Filter

Fully Automatic Carbon Steel and Stainless Steel Filter, Self-Cleaning Vertical Filter, Automatic Blowdown Filter

$37,500.00