Zoeller 4292-0027 Model MX4292 Explosion Proof Sewage Pump 0.5 HP 115V 1PH 25' Cord AutomaticZoeller Model MX4292 Explosion Proof Sewage Pump Description Our Model MX4292 is the industry's only automatic explosion proof pump rated for Class 1, Division 1, Groups C & D or Class 1, Zone 1, Groups IIA & IIB. The 1 2 HP MX4292 is a fully automatic sewage pump that is equipped with a brass float that prevents sparking in hazardous locations. The Pump's vortex impeller allows it to pass 2" spherical solids. The impeller's clearance in relation to