The BP5 Battery Tray for Pacific Laser Systems Lasers is a robust replacement battery housing that is designed for the PLS 3R/3G, PLS 5R/5G, PLS 6R/6G, and PLS 180R/180G lasers. Made of a durable plastic housing, it requires three AA alkaline batteries (sold separately). As an added feature, the BP5 tray only weighs 0.2 pounds and measures 4.1" L x 2.6" W x 1.3" H.