Includes: Installation Instructions, 4 No Flat Tires, 4 Axle Extensions, 1 Locking Hub and Installation Hardware. Why Our Wheel Kit Is Better: (1) Our axle extensions attach with three set screws vs. the leading competitor only uses two set screws. Therefore with our kit there are more points of attachment to the axle. (2) Our locking hub has eight points of engagement for the lock vs. the leading competitor who only has six points. Therefore with our kit there is less rotation of the wheel to get a locking position. (3) Our wheels are secured with a cotter pin vs. the leading competitor who uses a push nut. Therefore with our kit the wheel is attached more securely with a cotter pin than a push nut which over time could pop off.