The Nissin BM-01 Battery Compartment exclusively fits their Di466 & Di866 flash units, and is cleverly designed to be easy to use even in poor light. Having a spare set of fresh batteries ready to go makes a big difference when shooting on a job.
All the batteries insert into this magazine compartment in the same polarity direction; having all the 'male' parts of the battery facing towards the battery door's a heck of a lot easier to remember on location in a dark room. The batteries themselves are pushed into the clip in exactly the same manner; you don't have to push down on a spring with the blunt end of the battery to wedge the battery past a narrow spot.
They've also designed the battery compartment to prohibit accepting incorrectly-oriented batteries; you'd have to push it in there by brute force, and the fact that it wasn't going in would alert you to the problem.
The Di466 accepts alkaline, lithium, NiCad, and NiMh batteries.
BM-01 Battery Compartment for Di466 & Di866 Flashes
1-Year Warranty (Full Nissin USA Warranty)