I picked up this red lid to go with my 4-quart Pyrex mixing bowl, and it does exactly what I hoped. It snaps on snugly and turns the bowl into well-sealed storage, so leftovers and dough go straight into the fridge without plastic wrap. The red colour also makes it easy to spot on the shelf. It is designed for the 4-quart mixing bowl and the version with the red lid, so just check your bowl before ordering. Simple, sturdy, and genuinely useful.