Many original fitment pistons for these bikes were the'filled' solid type. These are lighter hollow pistons as fitted to more modern calipers, which not only reduces unsprung weight but also makes the pistons far easier to remove when your calipers are next due a service.We also offer full seal rebuild kits for most calipers, either radial type or traditional. The item "Kawasaki ZXR400 R H1 H2 J1 J2 89-90 stainless front brake caliper pistons set 8" is in sale since Friday, January 11, 2013. This item is in the category "Vehicle Parts & Accessories\Motorcycle Parts\Other Motorcycle Parts". The seller is "powerhouse-uk" and is located in Chesterfield, Derbyshire. This item can be shipped worldwide.