Item Type: StringWinderMaterial: Plastic + MetalBattery Type: Lithium battery (shipped with built-in battery)Battery Capacity: 800mAhThe Highest Speed: 15KHzOvercharge Protection Voltage: 4.3VWorking Voltage: 2.74.3VWorking Speed: 5 R/MinCharging Time: 2-5 Hours .wang-edit-text{ font-family:'Arial' important; } .wang-edit-text table { border-top: 1px solid 000; border-left: 1px solid 000; } .wang-edit-text table td, .wang-edit-text table th { border-bottom: 1px solid 000; border-right: 1px solid 000; padding: 3px 5px; } .wang-edit-text table th { text-align: center; } 1The multi-function winder can be used to wind or tighten the strings of any instrument 2Suitable for guitar, banjo, violin, bass, suitable for most acoustic and electric guitars and any other stringed instruments 3The unique shape of the puller can work easily and happily without damaging the guitar bridge 4Electric winder and reliable thread cutter, simple operation, time-saving and labor-saving, convenient for daily use 5Due to the compact and lightweight design of the multi-function winder, very easy to store and carry