Includes three B6-4 rocket engines, four model rocket starters, and four starter plugs. The B6-4 is a medium impulse engine that delivers high altitude flights. It works great for launching larger, heavier rockets, too. <br /><br /> Use the B6-4 engines to launch the Generic E2X, Alpha III, Wizard, Viking, Alpha, and other compatible model rockets. <br /><br /> ***PLEASE NOTE: This item will ship by US Postal Service only. You MUST HAVE a physical mailbox or Post Office box for delivery. <br /><br /> Engine Specifications: <br />Length: 2.80" (7cm) <br />Diameter: 0.70" (18mm) <br />Estimated Weight: .63 oz. (17.9 g) <br />Total Impulse: 5.00 N-sec <br />Time Delay: 4 Seconds <br />Estimated Max Lift Weight: 4.0 oz (113 g) <br />Max Thrust: 12.10 Newtons (2.7 lbs) <br />Thrust Duration: 0.80 Seconds <br />Initial Weight: 0.63 oz (17.8 g)