From the Tremco Products page....
Vulkem 116 is a one-part moisture curing, gun grade polyurethane sealant. Vulkem 116 is durable, flexible and offers excellent performance in moving joints. Vulkem 116 does not require a primer on most construction materials.
Vulkem 116 is an excellent general purpose sealant designed for use in precast, masonry, window frame perimeters and similar types of construction joints. Vulkem 116 is suitable for continual immersion in water. Vulkem 116 is designed for exterior and interior use.
-"You want to make it two inches - or, if you're working in centimeters, make sure it's enough centimeters for two inches."-Red Green