Slam Specialties' brand of high quality, high performance AirSprings has 4 sizes currently available: 5", 6", 7", and 8" diameters, and 3 pressure models of each (RE only for the 5"). All models are size and bolt pattern compatible with Firestone air springs. Size and bolt pattern is where the similarity ends. Slam Specialties' line of AirSprings are constructed with steel bead rings within specially-designed dual-end closure plates. All plates are permanently bonded (instead of clamped or crimped) to a technically advanced non-ballooning rubber bellows, making it virtually impossible for the plates to separate from the rubber - even unrestrained at maximum pressure.