Empress Effects ECM-519 500 Series compressors (6 total)

API Audio 500-6B 6 Slot 500 series Lunchbox w/ PSU - Pre-owned Home Studio

Alctron 500 Series Chassis + Fredenstein Preamp and Compressor Modules

Retro Doublewide II 500 Series Tube Compressor

Lindell 7X500VIN Vintage 500-Series Fet Compressor

Lindell Audio 7X-500 Series FET Compressor/Limiter

API 500-6B 6-slot 500 Series Lunchbox

Fredenstein Artistic Leveler 500 Series Optical Compressor Module 2