MBTB-25 Heavy Duty Tennis Ball Cannon model. It comes with a pneumatic trigger. It has a fixed barrel measuring 36" x 2.5". This easy to handle Tennis Ball Cannon can shoot well over 150 yards on every shot with compressed air as the fuel. No special tools or parts are needed. The cost of the MBTB-25 Heavy Duty Tennis Ball Cannon blueprints are: $20.00