Snapware® Total Solution® 中型方形塑膠蓋（含淺藍色密封圈）

The light blue seal is a nice touch—it’s easy to spot when the lid’s on right, and it’s held up through dishwasher cycles without warping. Fits the 4-cup square container perfectly, and I’ve tipped it sideways in my bag with zero leaks so far.

Finally, a lid that actually seals without fighting it. The light blue seal makes it easy to spot when it's fully closed, and it stays shut during my commute. Definitely solved my leaky container problem.

The seal on this lid actually stops leaks — I turned a container of soup sideways in my lunch bag and nothing came out. Snaps on tight enough that I'm not worried about it popping off in my backpack.