A new parking closure for ITW MaxiGrip’s plastic zippers: the slider remains in a parked position and does not require removal from the zipper. The Ultraseal nonporous slider closes in one direction and opens in the other; in conjunction with MaxiGrip’s plastic zippers, the assembly is virtually waterproof, airtight, gas tight and resistant to chemicals. For use in products such as waterproof bags, cargo storage, outdoor gear, electronics and document containers. Stronger than traditional pull-tab zippers, when zipped closed, Ultraseal provides reliable protection from the elements. Weldable, offered now in black polyurethane, and soon in polyester and polyethylene.