The MAC-4 multiple Appliance Controller allows up to four appliances with power venters or draft inducers to be interlocked and commanded. It puts an end to wiring problems which can increase costs and waste time. A solid state design provides variable voltage input power ranging from 18 to 130 vac and allows easy interlock with 24 vac and 115 vac control systems. This eliminates the need for voltage-specific relays. The circuit board is housed in an oversized 18-guage electrical box with multiple knock-outs for easy wiring.

Tjernlund Products, Inc. 1601 Ninth St., White Bear Lake, MN 55110-6794; 800/255-4208.