Back works fine, takes AA batteries. Frame spacing is pretty much darn near perfect. I put a sacrificial roll through the back just now prior to taking pictures, so you can see the frame spacing(I traced the outline of each new subsequent frame). Has some wear on the outside shell, but if you want a good user back, this can be your ticket to faster shooting

FYI, this back also works well on technical cameras(like an Alpa), using the RB adapter plate.

$120 shipped/Paypal'd in the USA
USPS Money Orders are fine too
AA batteries I used for testing the back will be included in the sale

thx,
Dan