Model 301 Valu-Pac 6-pk. Safe/Natural Value Pac6 Sack-Up Silicone Treated. Contains 6 Model 300's Rifle/Shotgun Sack-Ups. Sack-Ups are Silicone treated to prevent rust and to wick moisture away from your firearm. They provide protection for your firearm in the field or in storage and prevent dings and scratches. Keeps your firearm looking as new as it did the day that you bought it.