The retracts are made of heavy duty aviation grade aluminum. These are specifiaclly designed for the HET L-39 90mm jets.

Features:

• Air retract design for 90 size airplanes
• New designed control valve with adjustable air operated switch
• Made of heavy duty aviation grade aluminum
• Air up and down
• Operating pressure 100 PSI
• Suitable for Jets, Warbirds up to 13lbs./6 kgs
• For 8mm diameter struts 

Includes:

• Retract unit x 3
• Air tank x 1
• Control valve x 1
• Fill valve x 1
• Tubing x 2mm
• Three way tee fittings x 3
• Four way tee fittings x 1
• O-Ring set x 1
• wooden ring X 1
• Allen wrench x 2
• Threaded wire x 1