Made of linear food-quality polyethylene. Fitted with inspection plug and multiple ports for filling, draining, venting with 1" 1/4, 3/4", 1" female threads. Ready to fit a level indicator with 5-bore VDO flange (27.160.xx; 27.161.xx; 27.166.xx).Prepared for level indicator installation with VDO 5-hole flange (27.160.xx; 27.161.xx; 27.166.xx).