Our Manual Buckle Crimper and Sealer sets tension on 3/8"- 3/4" poly strapping to prevent contents from loosening or shifting. The strapping sealer uses leverage, rather than body strength. It lifts sealed strapping, holds and cuts without allowing strapping to snap back, and prevents injuries. After it squeezes and crimps the metal strapping seals it forms a no-slip grip on the 1/2" Polypropylene Strapping.