"These are by far the worst besa box gaskets I have ever used, and I get through a lot every week. I was caught short last week though at work so had to grab these + some lids (which were good) from a local screwfix. The gaskets are paper thin, they are not truely round, so don't seal nicely and virtually all of them still had off cuts attached from the moulding process which I had to trim off myself. Not recommended at all. Not worth returning them for the cost of them against the distance I'd need to travel to take them back, otherwise I would. Photo shows how they are not a truely round. Never had a bad product from screwfix before but felt this needed to be shared. May well be a faulty batch but I personally won't be trying these again."