●Package information: 2 wheels, 2 sleeves, 2 wheel bolts, 2 screws, 1 tension bolt, 4 flat washing machines. Note that there is only one extension screws installed on the side of the variable speed frame. ●Wheel diameter: approx. 13.5 cm / 5 1/3 inch, and the metal support bracket thickness is 3.5 mm, for extra stability and safety ●This set of heavy duty rear wheel stabilisers supports young learners to ride a bike until they have developed a usable sense of balance on the bike ●Suitable for childrens two-wheelers from 16-24 inches in estate 65288; except Huffy brand bike in the combi 65289; comes with fittings, easy to install, the brackets are individually adjustable. ●This product can be used on single or variable bikes and supports riders up to 100 pounds