Not surprised the gamma lids are in short supply.
You can just use the standard included (free) bucket lids. they should have a big rubber o-ring in the lid.
The only benefit of the gamma lids is they are easy to open/close if you are in them all the time.
Get a bucket opener. It's a big plastic "F" looking thing. Allows you to easily pry the tight lid off. Just re-seal with a rubber mallet.
You can just use the standard included (free) bucket lids. they should have a big rubber o-ring in the lid.
The only benefit of the gamma lids is they are easy to open/close if you are in them all the time.
Get a bucket opener. It's a big plastic "F" looking thing. Allows you to easily pry the tight lid off. Just re-seal with a rubber mallet.