The mechanism is sold separately and is Product #RC800. It needs a separate servo or push/pull linkage mechanism to operate the bomb drop. Creative use of a flap servo or rudder could be considered if you have no more available channel space on your radio receiver. Very little throw is necessary to release the bomb. Servos as small as 2.2 gram handle it just fine. Mechanism includes an extra clip for use on what ever you like. These are sold individually and should retail for $6.99 each. See Photo and they are now available. There is a “combo” also available Product #RC850 and includes one bomb and one mechanism. It should retail for $13.98.