Hydrocollator Heating Units remain the benchmark against which all others are judged. Durable and easy to maintain, these high quality stainless steel units provide a constant supply of temperature consistent HotPacs. Model M-4 Heating Unit • Complete with 24 Standard Size 10" x 12" (25cm x 30cm)HotPacs • Our largest mobile heating unit. • Requires just 20" x 32" floor space. • Extra-large tank, with oversized drain. • Includes 24 Standard Size HotPacs Supplied ready for immediate use and requiring no special plumbing, Hydrocollator Heating Units Feature: • Fiberglass insulation for reducing heat loss and maximizing energy efficiency (except for the E-1 and E-2 Heating Units). • Easy to maintain. Simple to fill and drain. No plumbing required. • 3" (7.5 cm) swivel-type rubber casters for silent, friction-free movement of mobile units. • UL listed, CSA certified.