Optical compressor, good for bass or guitar, simple to use, works perfectly. Rear rubber pad is off for application of velcro for pedalboards.
Features include:
Studio-grade optical compression
Output and Threshold controls
1MEG Ohms input impedance for proper pickup loading
1K Ohms output impedance when engaged
1% metal-film resistors for consistency
High-voltage poly caps for better tone
Military-spec circuit board for reliability
Blue status LED for high visibility and low power consumption
Easy access battery compartment
True hardwire bypass