Flex Caulk Silicone (100% silicone caulk) are our latest innovations in caulking technology. They are delivered through our Adjustable Trigger Flow Nozzle, which eliminates the need for a caulking gun and allows you to control the flow of caulk. Just adjust the flow setting and push the trigger for a perfect bead. And when you stop, it stops. There's no running, no dripping, and no mess.