Mr. Fantasy,
In top post you said CM-300. In a lower post you said CM-100. These are 2 different beasts. The CM-300 take the special 9V batteries, but CM-100 can run off AA batteries.
Which do you have? The bodies are labeled as CM-100 or CM-300, and on the attenuator bodies (the head) CM-100's have 2 wide slots, and CM-300's have 4 narrow slots.
Joe