As wonderful as the Game Ready therapy system is, just like other mechanical items, parts can break down over time. That includes the O-rings that are part of the Game Ready Hoses. Eventually the rubber O-rings used at all the hose connections will need to be replaced. Over time, as rubber does, the O-rings may swell, crack, rot, harden or otherwise degrade. A problem will be noticed when the unit starts having issues with leakage, difficulty in plugging in a hose, certain error codes appear, etc. If hardening is the issue, a little silicone spray (available separately) to lubricate might solve the problem. If not, this kit which has 10 Replacement O-rings, is here. To replace, gently remove the damaged O-ring being careful not to scratch the metal connector. Replace with a new-O-ring and carefully secure it in place, being sure not to over-stretch or twist the O-ring. Work is done when the O-ring is secure 360 degrees in the groove. Please note, this is the Hose O-Ring Replacement Kit Only. Game Ready wraps, control unit, hoses and all other accessories are available separately. If unsure if the O-ring should be replaced, try a little silicon spray first to see if that resolves the issue.Replacing the O-ring, while not overtly complicated, does requires some basic mechanical ""do-it-yourself"" skills and a comfort level working with tools. Users may find it helpful to work with a tool to help remove stubborn O-rings or securely and properly place the new ones. When using a tool, users must be careful not to scratch the metal connector. Before work starts on replacing O-rings, ensure the Game Ready hose is disconnected from the control unit. This O-Ring Replacement Kit is applicable to all Game Ready systems.