A 40T barrel ONLY by Diamond Pacific Tool Corp. is an industrial grade polyethylene barrel, SKU 611-14002. This barrel does not require any liner. Lids are made water tight for inserting a neoprene rubber gasket between the barrel and the lid. Weight of the barrel 5.5 lbs. with a load volume of 4 gallons, and with a weight capacity of 40 lbs. of stones and media. The photo shown is for the complete tumbler to give you an idea of what the barrel looks like.