FENDER Patented Callus Builder & Finger Strengthener – Resistance Finger Exerciser for Guitar, Bass & Violin – Guitar Finger Trainer & Grip Strength Tool – Ideal Guitar & Bass Accessories (Tensions: RED=8-Lbs; BLACK=15-Lbs)
Condition: New
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FREE 30-day refund/replacement
To qualify for a full refund, items must be returned in their original, unused condition. If an item is returned in a used, damaged, or materially different state, you may be granted a partial refund.
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Availability:
In Stock.
Arrives
Saturday, Apr 25
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Size: 8-Lb
Color: Red
Features
- ESSENTIAL GUITAR & BASS ACCESSORY From beginners to pros, this must-have guitar finger trainer improves strength, coordination, and enduranceperfect for daily guitar training or warm-ups before a performance.
- LICENSED and PATENTED FENDER CALLUS BUILDER Designed in the shape of Fenders iconic Stratocaster, this officially licensed guitar callus builder is a standout in any collection of guitar & bass accessories.
- RAISED STRING-LIKE RIDGES Unlike typical strength training grip strengtheners, this exclusive patented design includes raised ridges that simulate real string tension to help build callusesideal for realistic guitar finger exerciser practice.
- MIRRORS PLAYING POSITION Ergonomically shaped to replicate your hand and finger angles while playing any stringed instrument, making it a versatile tool to build calluses where you need them
- HIGHEST TENSION AVAILABLE Choose from 8-lb (RED) or 15-lb (BLACK) resistance. The BLACK version delivers extreme resistanceunmatched by any other guitar finger trainer or hand exerciser on the market.
- PERFECT HOLIDAY GIFT & STOCKING STUFFER A thoughtful holiday gift that shows you support their musical journey. The ideal add-on for anyone receiving a new guitar! Compact, affordable, and fun to use musicians of all ages LOVE this in their stocking.
Color: Red
Material: Plastic
Brand: Fender
Item Weight: 3 Ounces
Style: Wrap
Brand Name: Fender
UPC: 891922002216
Manufacturer: Barrett Productions, LLC
Item Type Name: Callus Builder
Warranty Description: NO
Color: Red
Style: Wrap
Item Shape: Variety
Item Weight: 3 Ounces
Material: Plastic
Tension Supported: 8-lbs or 15-lbs
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Saturday, Apr 25
Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Similar Products
Top Amazon Reviews
Size: 8-Lb, 15-Lb
Color: Red, Black
As stupid as they sound, they are really good. The red one seems the most useful as the black one has a MUCH higher tension, and I just don't find I need the extra "workout". I use it mostly when I'm away from my guitars as it helps maintain the calluses.
Reviewed in the United States on February 24, 2026 by Colin
Size: 8-Lb
Color: Red
Works great. I never seen anything like this. I've been using it to strengthen my fingers but the callus strips work awesome. I've been able to practice longer without my fingers hurting from the strings. The price I thought was a little high but now I think its worth it. I like the color but that wasn't important to me. I would recommend this.
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Reviewed in the United States on February 21, 2026 by J
Size: 8-Lb
Color: Red
This is my 2ed one and booth springs broke in about 3 months . Im not buying another one. Will ask for new spring.
Reviewed in the United States on January 23, 2026 by Pockets
Size: 8-Lb
Color: Red
Seems to help maintain callus as described and is comfortable to hold. Useful to fidget with while I'm working on other things. Makes a slight creak as the plastic hinge wears. And the magnet on the back can't even hold it's own weight on a metal surface so that part is useless. Has not broken yet but curious how long it will last. For 20 bucks I expected a higher build quality.
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Reviewed in the United States on November 9, 2025 by Remington Churchill
Size: 8-Lb
Color: Red
It has a magnetic on the back, it's also a potato chip bag clip ( too funny but true) It has strong resistance and starts to build calluses on fingers after just a few days!
Reviewed in the United States on February 4, 2026 by Chuck M
Size: 8-Lb, 15-Lb
Color: Red, Black
I recently started up playing guitar again after taking a hiatus for a couple years. Unfortunately, the calluses I built up long ago faded away. I bought this set of callus builders to see if I could accelerate the process of building up callus. I debated buying only the 15 lb. device but opted to pay a little more and buy the set of both the 8 lb. and 15 lb. devices. I’m glad I did. Both weights will strengthen your fingers and help build callus, but my 70 year old fingers found the lighter one easier to use, at least until I can build up more finger strength. But both are definitely helpful, and they’re easy to use while watching TV. My only complaint is these devices are somewhat small. I have to bunch my fingers up a little bit to fit all 4 fingertips on the device to build callus. It would have been better if these were about 1/4 inch wider. Overall, I’m pleased with these callus builders. They’re kind of expensive for glorified potato chip bag clips, but they work as advertised, and I’m sure I’ll get a lot of use out of them.
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Reviewed in the United States on December 1, 2025 by Terry R. Nye
Size: 8-Lb
Color: Red
Product works as advertised. Great way to strengthen hand and fingers while building calluses at the same time.
Reviewed in the United States on February 19, 2026 by Mike Welch
Size: 8-Lb, 15-Lb
Color: Red, Black
Good but super cheap on the magnet... that needs to be replaced. See photo -- instead of a proper sized magnet, they put a far smaller magnet under a tin cap. It can barely hold the item. Now I have to source two magnets, and replace them. Lame.
Reviewed in the United States on February 27, 2026 by DP