This is a set of Centurion retracts by Century Jet Models for the Top Flite P-51D Mustang. They are 90°, Non-Rotating, Pneumatic Retracts for Planes 10 - 15lbs. FEATURES: Positive over center UP and DOWN locks One piece machined aluminum air cylinder with larger piston diameter for more power. Investment cast Stainless Steel cam System weighs only 14oz (including air system) Offset struts (for wheels up to 4") for scale P-51 appearance Fully functional oleo struts Stainless steel strut housings and anti-torque links INCLUDES: Two Main Gear Retracts (left and right) w/Axles One Air Tank One Air Tubing (5"-Black and 5"-Red) Two Quick Disconnects Three Tee Connectors One Filler Valve One Control Valve One Instruction Sheet SPECS: Retract unit: Mount plate: 1-3/4" wide x 1-1/2" long x 1-1/8" depth Overall unit (inside plane): 1-3/4" wide x 4-3/4" x 1-1/8" depth Strut: Length: 6-1/2" Diameter: 3/8" Axle diameter: 3/16" Air tank: Length: 5-3/16" Diameter: 1-1/2" REQUIRES: Bicycle Pump (capable of 100 psi) for Pressurizing System. 5-11-95/eke ir/jl