Fits Holley 4150 and Carter AFB (late), 200-500 HP, includes Black 10

NOS Pro Two-Stage wet nitrous system gives you a moderate shot of nitrous at the line to get a solid start. Then, a second stage of nitrous gives you serious muscle through mid-track and the top end. This system is adjustable from 200-500 horsepower and uses a special dual stage plate design for excellent nitrous flow, fuel atomization and mixture distribution. Our Big Shot style Pro Two-Stage plate utilizes 4 unique spray bars equipped with tiny orifices precisely located to efficiently dispense a powerful nitrous/gasoline mixture for unbelievable horsepower gains.