The arrangement of the battery pack is rotated 180° from the Milwaukee vs. The Bosch. These batteries are all probably made in the same plant and have small differences layout wise to make them incompatible. The cheap12v stuff from true value has similar packs that won't fit either.I didn't believe it at first but they looked so similar when you put pictures next to each other. Especially with the hackzalls. I figured it could have been some sort of licensing agreement. Thanks for clearing that up.