Hand Pump with built-in pressure relief valve Threaded rams with improved hand wheel style safety nut Quick rising center extension Easy access filler/breather cap Heavy-duty wheels on all aircraft tripod jacks where spring loaded casters are not standard Hydraulic fluid: MIL-PRF-5606 3/4 in (2 cm) spherical radius cup jack pad Finish: Durable Powder Coat Tronair Blue