Attention 2 & 3 Speed Racers!Biondo Racing has put together the easiest RPM activated switch to program, with Auto Reset! This switch features microprocessor controlled timing which retains numbers when powered off. The large LCD screen is easy to read. These units work with 4, 5, 6, 8, 10, and 12 cylinder engines. Each features a 3000-9900 RPM range that can be changed by pushing the buttons on the face of the unit. The test feature allows you to test your shifts by holding either button down for 2 seconds. There are two separate outputs - one for normally open, and closed (for CO2, air, or electric shift applications). The units can also be programmed so it won't activate again at the finish line. This will save air for vehicles using air or CO2 shifters.