I was sold this for my 450a and it’s incorrect. Contains 12 pcs. The JLG 2901284 Seal Kit is specifically designed for the hydraulic cylinder on telescopic boom lifts, compatible with models 600S and 660SJ. This kit includes essential components such as rings, o-rings, seals, and wipers to ensure proper functionality and sealing of the hydraulic cylinder. Manufactured by JLG, a trusted brand in the industry, this seal kit is tailored to fit JLG equipment, providing high-quality and reliable maintenance solutions for boom extension systems.