M-4 Mobile Heating Unit with 8 Oversize & 8 Cervical HotPacs * 110~120 V 50/60 Hz * High-quality stainless steel * Thermostatically controlled temperature * 3 (8 cm) swivel-type rubber casters for silent friction-free movement * Easy maintenance * Simple to fill and drain * No plumbing required * Uses 110 current 12.5 amp * One-year warranty * Full fiberglass insulation on mobile units to ensure minimum energy use and prevent heat loss * Requires just 20 by 32 floor space * Extra large tank