Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Durability Concerns

I received the unit intact but before first use, the goggles broke by means of a peice of plastic attaching the strap to the mask. Thus, I did not even get a chance to use the goggles so they may in fact work nicely provided you carry them everywhere in a pillow.The snorkel is extremely heavy and the unit which I had problems with the valve at the top which prevents water from entering. The valve stuck way too much, even after lubricating, causing a reverse affect where you could not breathe even when you didn't have water in the tube. The weight also causes it not to stay upright if using other goggles.I'd recommend sticking to the Seabreeze and Cozumel set, from my experience at least.