IDEAL Duct Seal, 1 lb and 5 lbs

IDEAL 1 lb. and 5 lb. duct seal in dark gray putty color is ideal for sealing metal, masonry, wood or plastic. It offers 1.65 specific gravity and is non-toxic. It has calcium carbonate, magnesium aluminum silicate, crystalline quartz silica, butane polymer, synthetic polymer, carbon black, antioxidant, cellulose fiber, aluminum silicate, tall oil rosin and naphthenic wax composition. 

Features: 

• Moisture and air barrier
• Seals around junction boxes, flashings and service entrances
• Permanently soft, non-toxic compound can be painted immediately after application
• Won't adversely affect other plastic materials or corrode metals