The Diamond Crystal Bright & Soft Salt Block is 50 lb. of value just waiting to be added to your household. The salt block contains up to 99.8% pure salt. This salt is virtually 100% water soluble, and specially formulated to prevent mushing and bridging in the brine tank, helping to keep your softener clean and trouble-free. The product is recommended for all softeners and its purchase is backed up by a limited warranty.