I've had two sets of Kerry covers on two different ships. The first set, purchased from Wings and Wheels, held up very well. Manufacturing was without issues, and the covers yellowed slightly over a period of several years with frequent use. I ordered the next set for use with a DG-400 even before the glider arrived. Quality and performance of the second set is identical to the first. I expect to get anywhere from a half-dozen years to a decade out of them. Typical usage is a couple of nights on the weekends throughout the season (glider is stored back in the trailer during the week) and some extended periods of up to a month or so during soaring trips or encampments where I am flying most days and choose to leave the ship tied-out.