The ACDelco 12378521 RTV Engine Sealant is the sealant used in GM engine plants. Reseal your engine components with the same high-quality sealer used in the GM Production Line. ACDelco RTV Engine Sealant is a one-component, room-temperature vulcanizing (RTV) sealant. It is a high viscosity product that cures when exposed to air. The cured material has superior adhesion and elongation properties and is resistant to engine oils and coolants. It is also oxygen sensor safe and will not corrode metal surfaces. 

Features: 

OEM Sealer 
GM Part#: 12378521
AC Delco Part#: 10-2010

Specifications
MFG. Number
12378521
Manufacturer Name
GM / ACDelco
Shipping Weight
2.00 lb.
Shipping Length
2 in.
Shipping Width
2 in.
Shipping Height
5 in.
Fuel Type
Diesel / Gas
UPC
707773905036
Prop 65 WARNING: Cancer & Reproductive Harm – P65Warnings.ca.gov Internal
L0.00R4.00