Trapezoidal shape means more air at the top, creating a shorter, lower profile bag. Ideal for inflation inside tight spaces. Intended for lifting heavy objects. Lift Bag contains an internal dump valve with pull cord that is used by the diver ascending with the bag to control ascent rate. Open design means air will vent out the bottom in case of a rapid ascent. Self-storage pocket makes stowing and carrying the bag a cinch. Made in the U.S.A. Please Note: Lift Bag Storage Sleeve is NOT INCLUDED with the Lift Bag, Sleeve is sold separately. Salvage divers, underwater archaeologists or anyone who needs to recover a heavy underwater object will appreciate the design of this lift bag.