myredracer wrote:
"Pexlock" is from Flair-it. The clamps are made from plastic, the same type of plastic as the fitting the OP had split on him. Very little info. that I can find on them. I can't find anything that says the clamps are permitted by code.
Not something I would use. As far as I'm concerned, you can't beat copper PEX rings. A proper PEX crimper can be had for as low as $30 and the rings are dirt cheap.

The plastic rings may or may not be OK, but the plastic tees and elbows are definitely not. The OP is not alone in having issues because of them.