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
Monday, May 25
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Size: 8-Lb, 15-Lb
Color: Red, Black
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 Included both 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, Black
Material: Plastic
Brand: Fender
Item Weight: 6 Ounces
Style: Guitar-shaped
Brand Name: Fender
UPC: 891922002230
Manufacturer: Barrett Productions, LLC
Part Number:
Model Number:
Item Type Name: Callus Builder
Warranty Description: No.
Color: Red, Black
Style: Guitar-shaped
Item Weight: 6 Ounces
Material: Plastic
Tension Supported: Heavy
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Monday, May 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
work good
Reviewed in the United States on April 30, 2026 by Thrillbilly
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
Does what it's supposed to do; that is help you develop callouses, to make playing guitar easier, and more effective.
Reviewed in the United States on May 10, 2026 by flintlock
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: 15-Lb
Color: Black
I haven't experience any issues like some other reviews have talked about with the unit breaking after some days of using it. I've been using this mostly daily for almost a month now and it works very well. Plastic and rubber(or maybe silicone?) parts look and feel thick and sturdy. Maybe it would cause an issue if you squeeze very hard and fast over and over, but that's not how you should use this product anyway. The goal isnt to squeeze as hard as you can. I press hard but not too hard to where it's painful, slowly do a few reps squeezing the clip about halfway, causing deep imprints on my finger tips. Then i move my fingers left, right, up, down while i hold down on a single line. Which essentially just tugs the skin on your finger tips in every direction, causing your skin to want to callus even more. Honestly i think pulling the skin causes callus more than just pressure on an area. Haven't tried the magnet but it seems firmly attached by a blot of glue. The magnet does move around a tad so if you used the magnet on a daily basis i can see maybe eventually it would fall off and you would have to re-glue it. Really not a big deal. I'm honestly not sure why this isn't more of a common tool you see around. Searching Amazon this one is really the only one that pops up. Definitely works though.
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Reviewed in the United States on October 1, 2024 by Stephen McSpirit
Size: 8-Lb, 15-Lb
Color: Red, Black
This works. I, for some reason, don't seem to form callouses well/easily. Whether it's working out, yardwork or guitar - no callouses. But this gadget works! After a few days I could tell it was working. Easily by 2 weeks, I had solid callouses. I got it for Christmas and it's 1/31 now. I got both strengths and keep them on my desk during the day and use it various times all day. I'll use it when watching TV or similar times. I try to move it around so it's not hitting the same spot all the time. I change the angle too. I haven't been able to get callouses on the side of my index finger for barre chords but maybe I will in time???
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Reviewed in the United States on January 31, 2026 by Bear C.
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
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