Application: Suitable for most diesel applications, brushes are specially designed to fit injector seats. Function: This professional diesel injector-seat cleaning kit is used to remove rust, carbon and other debris from seats, bores and cups without damage. You can easily finish cleaning for the injector-seats and bores on most light, medium, and heavy-duty diesel motors with this kit. Description: New Helix-Style Brushes, Two-Stage Brushes and Bore Brushes 3", 4" and 6" brushes, Ideal for many automotive and industrial uses. Superior Quality: Made of premium quality stainless steel with wear resistance. .