If I remember right,it is to replace the B65 by 2 123A cells and this spacer. As the B65 is longer than the 2 cells, the spacer is needed incase the rechargeable battery is empty and still light needed. In this case the user can swap the B65 for two 123A's and this Z29 spacer. /ubbthreads/images/graemlins/wink.gif