Rectorseal 81880 1 lb Duct Seal Compound

Duct Tape by Rectorseal. Details: RectorSeal Duct Seal Compound is a gray, permanently soft, non-toxic, putty type compound which adheres to most clean, dry surfaces. It is designed to be used when sealing around the ends of electrical conduit and boxes. 10-Pound. RectorSeal Duct Seal Compound is a gray, permanently soft, non-toxic, putty type compound which adheres to most clean, dry surfaces. It is designed to be used when sealing around the ends of electrical conduit and boxes. 10-Pound.