I've had great success with other products from this company; however, I found these lids difficult to close tightly without worrying I was going to crush the cup and spill my delicious drink all over myself. The cup itself doesn't leak "much," but much doesn't cut it for me.Great for the ice coffeeThe lips are hard to attach. The cups are good.I bought these for a birthday party they are good but caps are difficult to attach. Otherwise this is a great buy! my tip print the guests names on mailing labels & stick on cups so they don't get mixed up ?They're really sturdy and so ready to be used.Lids are tough to put on to cup, but once on it is secure.It seems as if the lids are slightly smaller than the cup.I bought a wonderful set of clear plastic cups but the seller no longer exists. I tried another seller’s product and their cups were very flimsy. These cups are just like the cups I had purchased before; very well made and good thickness and resistance in a squeeze test. I wash and reuse my cups many times before recycling them and these cups hold up to repeated use.Thick plastic. Excellent quality.Good product, good for lots of different beverages