Had a leak in my 2850mk inside an inaccessible area. Think it's the feed hose to an outside hose coupler. The hose enters the hot water heater area, so I thought I'd cut the hose, use a nippled shutoff and hose clamp, till I can remove and fix the leaking hose. Guess what? 1/2 inch is too big, and 3/8 is too small. Dang pex hose! Forced the half inch on, temporarily, till I can get a 7/16" nipple. I'm old school, and do not want to invest in all the pex tools, but I may have no choice. I want to redo all my winterization area hosing to make it more accessable. Just a heads up.