The Vacuum 655 is designed to be used with the Primo Interferential 960 and Primo Multidyne 970 stimulation units. In addition, the Vacuum 655 can be used on any previous model of EMS interferential units purchased within the last 10 years. Lightweight Pulsed or continuous vacuum Powerful new super-quiet vacuum with virtually no vibration Channel selection option – Channels A+B or Channel A only Supplied with complete set of accessories Dimensions: 65 x 210 x 100mm (excluding water trap) Weight: 1.5kg Includes four vacuum electrode cups (60mm) each with sponge inserts, four vacuum electrode leads and one link lead to connect unit to interferential / stimulation unit.