Optical compressor, good for bass or guitar, simple to use, works perfectly. Rear rubber pad is off for application of velcro for pedalboards.
Power supply NOT included.
If you're seeing it, it's available.
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