ZEX Nitrous Injector Perimeter Plates convert and update any spray-bar type nitrous system application into a ZEX Perimeter Plate System. This cost effective and easy to install upgrade immediately delivers all the benefits of the Perimeter Plate System without having to purchase an entirely new system. Perimeter Plate injection results in more even distribution of fuel and nitrous for maximum power and engine safety. Includes plate, gaskets and jet conversion chart.