The base unit has three slots that are compatible with all available Preymaster memory cards for up to 12 available sounds. The memory cards contain the authentic Johnny Stewart sounds that have been digitally remastered. The included Digital cards are MC-BC1 (BobCat Calls, Volume #1), MC-CY2 (Coyote Calling- Volume 2), and MC-GP2 (General Predator-Volume2). The base unit will play continually until shut off and operated on 4 AA batteries. There is a clip on the back of the base unit to attach the remote transmitter and a mount on the front to hold the speaker. The speaker has a 110+ db rating. A 10 extension cord is included to allow the speaker to be elevated while the base unit remains safely on the ground. The base unit measures 8.1 x 2.84 x 1.3 inches and the remote 6.1 x 2.55 x 0.87 inches, making the PM-4 compact and easy to transport with a total weight of 2.3 lbs. The Johnny Stewart PM-4 Wireless Preymaster from Hunters Specialties is a rugged, dependable unit that will satisfy the needs of the most dedicated predator caller, yet is affordable and easy to operate for beginners as well. Manufactures Website Address www.hunterspec.com Warranty Information