Thank you for viewing. After purchasing new, I only used it indoors, and I haven't applied Velcro or anything to the back. Below is the description from the manufacturer's website: A stereo modulation pedal equipped with three historical modulation algorithms. This is a flagship modulation effects pedal equipped with a powerful dual-processor UAFX engine. It features algorithms for classic vintage effects such as chorus, flanger, and tremolo. ・Chorus Brigade Perfectly models a classic 1970s BBD-based, Japanese chorus/vibrato effect pedal. ・Flanger/DBLR A rack-type flanger/doubler effect that was once widely used in studios. ・Trem 65 Recreates the optical tube tremolo found in blackface tube guitar amps that appeared in the mid-1960s. A conductor of a starry ensemble that colors the sound of magic. Astra will show you a colorful sonic universe. Specifications ■ Input Terminals: 1/4-inch TS phone × 2 (Input 2 is for stereo connection) ■ Output Terminals: 1/4-inch TS phone × 2 (Output 2 is for stereo connection) ■ USB Terminal: Type-C