Double wall tank, external tank in galvanized steel and internal tank in high density polyethylene, suitable for the storage of waste oil and diesel. Including 4 connections in 2” on top of the tank, mechanical level indicator, optical leakage detector for eventual leakages in the internal tank, carrying handles and pallet feet for the lifting and the transport with a pallet truck or a forklift from 4 sides. Approved for indoor installations.