I have MDC Hyper Throw, MDC Body Guard, MDC 123 NW, and MDC 123 CW. I tested all with newly redesigned body, everything works except MDC 123 CW which is older model. Since head is old and I noticed it poted deep compare to newer MDC 123, so top edge of barely touched negative contact inside of head. Anodizing is not problem I think. I will try to put some solder around inside of MDC 123 CW or attach some thin copper ring to solve the contact problems.