Parker's 59 Series is the premiere thread-to-connect coupling for high impulse hydraulic applications. The rugged Acme threads are resistant to damage and have a double start feature to quickly align the threads, saving time and eliminating frustration. As few as two and one half sleeve rotations will complete a full 59 Series connection. The bright orange O-ring is concealed by the sleeve and you can also feel when the coupler and nipple are fully mated, giving both a visual and tactile confirmation of a secure connection. Engineered to perform, the 59 Series was designed with an internal bearing to reduce hose twist and ease the difficulty of connecting fluid lines while under pressure.