3M #847 rubber and gasket sealant.

SPECS:
-Container Size Range: Smaller than 16 oz.
-Color: Brown
-Container Size: 5 oz
-Container Type: Tube
-Maximum Operating Temperature (F): 300
-Maximum Operating Temperature (C): 148.00
-Series: 847
-Series Part Number: 847
-Adheres To: Ceramic; Drywall; Fiberglass; Glass; Metal; Plastic; Rubber; Wood
-Clean Up: Acetone; Solvent
-Minimum Application Temperature (F): 65.00
-Minimum Application Temperature (C): 18.33
-Standards: MIL-C-4003