So-Low H121-4000-C Cryogenic Storage System was designed for the storage of cryovials in racks containing 25-cell or 100-cell boxes. Numbered rack system allows easy location and quick retrieval of samples. Limited opening maintain low vapor temperatures of -185C and provides economical evaporation rates. A locking provision for the lid is supplied for added security. These units are backed by a one year parts and labor warranty and a three year vacuum warranty. Units come complete with stainless steel racks and either polycarbonate or fiberboard boxes. A sturdy cast aluminum roller base with high retaining posts and 5 wheel locking casters provide safe and easy movement for full tanks.