SHIPPING NOTES: Due to the Coronavirus COVID-19 pandemic, USPS, and UPS have announced several service delays and slowdowns that will effect your ability to receive shipments in the estimated days to delivery. Please allow additional time for your order to arrive as the USPS, and UPS will now require more time for packages to be delivered due to limited transportation availability, and higher than normal online purchases as a result of the (COVID-19) pandemic.


Conspec Family Business BadgeConspec Warranty BadgeOne-part, neutral curing, medium modulus glazing silicone

Clear selection

BOSS – 399 100% Glazing Silicone

BOSS – 399 100% Glazing Silicone Sealant is a one-part, neutral curing, medium modulus sealant formulated for the window and door glazing market. It offers primerless adhesion to vinyl, wood and aluminum. For use as a primary back bedding compound as well as a perimeter weatherseal for field glazing and window installation. Bonds to Kynar 500, and is VOC Compliant in all 50 states. Special colors available upon request.

• VOC Compliant in all 50 states
• Low odor
• Excellent backbedding sealant
• Medium modulus
• Primerless adhesion
• Bonds to Kynar 500®



To view the most recent Technical Data Sheet, please click here.

Weight 20 oz
Dimensions 2 x 2 x 13 in
Product Color

Beige, Black, Bronze, Clay, Clear, Cocoa, White

You may also like…