Sack Ups Protector 6 Knife Holder AC. This knife holder manufactured by the experts at Sack Ups is silicone treated to prevent rust and to wick moisture away from your knives. The Sack Ups Six Knife Silicone Sack Protector will help keep your knives in pristine condition and looking new. Specifications for Sack Ups Protector 6 Knife Holder: Manufacturer: Sack Ups Closed Length: 5 in Package Contents: Sack Ups 6 Knife Silicone Sack Protector Sack Ups AC802: Protector 6 Knife Holder