This top of the line single message communicator has crystal-clear digital sound! Features easy single message recording, one-touch playback for up to 2 minutes, external switch jack and interchangeable switch tops. Connect a toy or battery operated appliance for instant positive reinforcement. Require 9-volt battery (not included). LITTLEmack is perfect for mounting, and is recommended for persons who can access a smaller activation surface. 2½" activation surface. 4"L x 4½"W x 3½"H.