Vacuum Generator series ZL series is a multi-stage, high-efficiency vacuum generator, which operates at 150% efficiency (compared to about 40% for other units). For each scfm of compressed air it consumes, the ZL generates an incredible 1.587 scfm of suction flow. The ZL is available with a built-in vacuum switch with digital readout for design flexibility. Other features include built-in suction filter, exhaust silencer, and one-touch tube fittings. Its' compact design allows for mounting from three sides.