Miracle Mudd's two part cement system assures long lasting strength and leaves the stained glass panel weatherproof. Use: Strengthen & waterproof leaded glass panels Shelf Life: Unlimited! Just mix what's needed for each project. (Mixed leftovers can be stored for short periods in an airtight container) Size: Small Set (Makes approx. 1lb. of Cement) Contains: 10.5oz. Miracle Mudd Powder & 4oz. Liquid Hardener Color: Black