FENDER Callus Builder and Finger Strengthener (Red 8-lbs) - For people who play any stringed instrument (Guitar, Bass, Violin, etc.)

ESSENTIAL GUITAR & BASS ACCESSORY - From beginners to pros, this must-have guitar finger trainer improves strength, coordination, and endurance-perfect for daily guitar training or warm-ups before a performance. LICENSED and PATENTED FENDER CALLUS BUILDER - Designed in the shape of Fender’s 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 calluses-ideal 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 resistance-unmatched by any other guitar finger trainer or hand exerciser on the market.