The Boss RC-20 is a user-friendly recording and sampling guitar looper pedal that features Auto Start and Loop Quantize functions, letting you quickly create perfect loops. This Boss looper pedal allows you to record a guitar phrase of up to 5 1/2 minutes. The Realtime Tempo Change function of the Boss RC-20 allows you to change the tempo of the samples while keeping the pitch constant. Add variety during a single performance with this guitar looper pedal that can store up to 10 phrases simultaneously. This Boss looper pedal lets you play stereo loops, so that you can control the overdubbing, speed, and tempo. This guitar looper pedal is an awesome guitar companion for the ambient rock piece that you want to nail.