Features:Excellent bass mid-range response and soft acoustic tone,Available for the guitar with 3 11/16" and 4 1/8" (94-105mm) diameter sound hole,The screwdriver is included,easy installation and removal.6.35mm Straight JackShock-adsorbing foam lines the inside edges of both mounting brackets.This magnetic pickup will work if the strings have some type of iron component within them,cannot work with nylon strings.The installation steps:1.Install it at the soundhole2.Tied the jack socket at the bottom strap lock3.Connect your amplifier with 1/4 mono jack guitar cable4.Turn on your amp5.You can adjust the height between the string and the pickup pole to acquire a different volumePackage includes:1 x Acoustic Guitar Sound Hole Pickup1 x Screwdriver