DetectingMO, where'd you find the bit about the batteries and coil?
Seems like these would be similar to the new Bounty Hunters: Lone Star Pro, Quick Draw Pro, and Land Ranger Pro. At least 2 of them use 9V.
Can't make out all the buttons on these Fishers. Power, pinpoint, up/down I see. I think Mode, too. Menu Maybe? Guessing the extra button on the 44 is Ground Grab?
Edit -- Found more info and clearer pix. I got all the buttons right. I ran this through google translate and could more or less read it: