1x 26650 to 2D kit uses a singe 26650 cell and the factory Maglite tail spring (We recommend using a protected cell to prevent over discharge of the battery.). Also included is an aluminum button that snaps into the factory spring to make contact with the negative end of the 26650 battery. The sleeve has a long brass screw inside to take up the extra space in the body. No other parts are needed for this conversion. This body kit is perfect for use with the Firefly 325 lumen, 1100 lumen or Lumencraft 2500 lumen bulbs. Sleeve dimension 4.4"L x 1.3"W.

This video outlines how to install the body kit.