Dual-battery waist-mounted weight reducer: It can reduce the workload of workers. It is equivalent to carrying a backpack with two batteries. Two fully- batteries can be stuck inside for long-term operation. The external pluggable 90CM extension cord interface is designed with fake battery interface, adapter (V6V7V8 common head). Two batteries consume power in parallel. This product link does not come with a battery. Greatlylncrease Vacuuming Efficiency: 2pcs for 18V Batteries Can Work Much Longer than 1pc Original Battery Convert for 18V Battery to Power for V6 V7 V8 Vacuums NOTE: You must remove your batteries from after use, or the adapter will drain your batteries until they run out. Tips: The product may be updated constantly ,Due To Different Batches, The Actual Product May Have Slight Differences Or Color Differences, Which Does Not Affect Use Color: black material: plastic Style:A Package Contents: 1 x battery adapter Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.