AccuTools DS-220R Refrigerant Charging Scale Portable has a 220lb capacity with 0.1oz resolution that is one the most feature-filled precision scales on the market. The AccuTools DS-220R is specially designed for HVAC and refrigeration work like Critical Charging on small systems with a patented lightweight rugged design and built-in handle for easy carrying. Also, the AccuTools DS-220R can be easily programmed, calibrated in-field, and includes charging alarms.