These are complementary parts, commonly found in our Customer's factories. Because all of Ustegra's products are customized solutions, so are these. Hence our wheels and hoses are not those regular items, easily found in a hardware store, but they are custom-made according to our specifications. Often this means special construction, or special material. Therefore there isn't any minimum order. A one-off or even one-piece order is fine with us, although we are more than capable to do series-production.