Big apology if this question is a repeat, but the search feature isn't working, so here it goes anyway.

The rules state that an AMB (MyLaps) transponder must be used. Simple web search and a few clicks later gets me this option:

Looks right, but before I pull the trigger it would increase my comfort if someone could confirm successful use of this item with the MRA in the past, as it's clearly different than the rental units.