The Guyatone SD2 Sustainer D is a versatile distortion pedal that emulates tube amp tone. It combines compression, sustain, and drive in a compact unit, offering everything from subtle boosts to creamy, violin-like tones. It provides arena-sized tone and endless sustain at any volume, making it ideal for guitar and bass. This pedal is a great alternative to using a compressor and distortion together, which can often be noisy.