Any wireless microphone system depends on sufficiently charged batteries in all the transmitters. There is nothing more embarrassing than a transmitter running out of juice in the middle of the show, or a voice fading as the transmitter battery dies.
The CU 400 charging unit puts an end to this kind of hassle. It can charge two batteries simultaneously to full capacity within one hour, and there is no risk of overcharging the batteries.
And what's best, you can leave the batteries inside the WMS 40 or WMS 450 transmitters. The transmitters and charger use integrated charging contacts so all you have to do is plug the transmitters into the CU 400 charging unit and remove them after charging.