Uniseals are used to attach pipe to just about any container in situation where bulkheads will not work. Smaller Uniseals are a good choice for making fermenting containers, hot sauces, barbecue sauce and many other home and garden uses. 3/16” Uniseals have an ID 0.15” (4mm); an OD of 0.25” (6mm); and a 0.3 (8mm) drill bit.