Moozikpro String Winder - 250 RPM Speed & Powerful Batteries 250 RPM SPEED - Much faster than traditional manual peg winders EASY TO USE - Makes restringing your instruments faster, more efficient & easier POWERFUL & RECHARGEABLE NiMH BATTERIES - No more dead batteries & power adapter included UNIVERSAL PEG HEAD - Fits bass, acoustic, electric guitar tuning machines & all tension requirements ABS FINISH - Compact and portable design anywhere you need a complete string change