Indicators - Diagnostics with indicators communicate battery health. Easy to install or remove - first install the adapter and tighten, put the battery into the adapter. Then steps to remove the battery for charging or replacement, release it from the adapter, and charge or replace the battery. Note: The adapter in the for 21.6V charger cannot be used to charge the battery! Please remove this adapter before charging the battery. For Converts all 18V Lithium Battery: (NOT fit for 12V CXT battery) BL1860, BL1850, BL1840, BL1830, BL1820, BL1815, -400, 194205-3, 194204-5, BL1820B, BL1830B, BL1830B-2, BL1850-2, BL1850B, BL1850B-2 Converts for 18V lithium battery to be for V6 battery, replacement for V6 series battery: 965874-02, 967810-03, 967810-02, 967810-23 SV03, SV04, SV05, SV06, SV07, SV09, vtc4 DC58, DC59, DC61, DC62, DC72, DC74 This 18V to 21.6V battery adapter is designed to run V6 series cordless vacuum, Compatible with: (NOT fit V7 V8 series vacuum) V6 Animal Vacuum, V6 Vacuum, V6 Trigger Vacuum, V6 Absolute Vacuum, V6 Slim Vacuum, V6 HEPA Vacuum, V6 Cord-Free Vacuum, V6 Fluffly Vacuum, V6 Car+ Boat Vacuum, V6 Top Dog Vacuum, V6 Mattress Vacuum 210759-04, 204720-01, 209432-01, 209472-01, 209476-01, 209560-01, 210691-01, 210692-01, 210405-01 Vacuum 595 650 770 880 Vacuum Tupe: Battery Adapter Model: MT18DSV6 color:Black grey Material:Plastic + Metal Suitable for 18V 4Ah and above batteries, not suitable for 3Ah batteries Package Contents: 1 x MT18DSV6 Adapter Only the above package content, other products are not included. Note: Light 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.