The is one of the following closely-related slotted block belay devices:
Each of these works much like any other slotted
belay device. The control is good, but not as smooth as some
of the belay tubes. Like the Wild Country Variable Controller,
the two ends are asymmetrical, so these can be reversed for a slight
change in feel. The asymmetry is less than on the Variable
Controller, and I don't find the difference between the two
orientations to be very great.
The cable keeper is stiff enough to not get caught by the rope.