What is the difference between “Extended” and 100% silicone sealants?

Extended” silicone sealants are mixed (or cut) with various types of oils & solvents, to varying degrees (sometimes up to 35%!). “Cutting” silicone with these materials is often done to increase the number of individual resale units a manufacturer can produce from a single raw material unit which can reduce the cost/unit, resulting in decreased performance. 100% Silicone sealants are comprised of 100% silicone and are not “cut” with any oils or solvents. The result is increased performance over “extended” formulations in the form of greater adhesion, less shrinkage, higher temperature performance, and lower temperature application.