4 Band Parametric. 4 Channel of EQ. Fully sweep range, excellent quality. RCA in/out but unit will do +14db, #8+ Condition, no rack rash, 1 incorrect knob top. Update P.S. grounding. Clean all controls, switches, 2 times. Aside of the fact these equalizers are on of the best ever designed, be aware, most PE-40 if roaded or excessively used do require in depth cleaning of all controls, switches, sometimes replacement of controls if damaged. This can require some time consuming dismantling. Some people want these in perfect working condition, others might find problems at bargain prices. We deal with the former, not with the damaged goods. All units are serviced, cleaned checked and come with a warrantee.