These kits come with (2) 1/4″ diameter taper threaded mandrels, 3/4″ long & 1″, assortment set of spiral wound sanding cartridge rolls from straight and tapered 60,80 grit to 120 finish grit. Diameter are 1/4″ 3/8″ 1/2″ for shaping blending corner radius and more on intake, exhaust ports. Work with air or electric tools cast iron or aluminum. Plastic storage case included. Please e-mail with questions.