The Viking VK3501 Quick Response Upright Sprinkler is a small thermosensitive glass bulb spray sprinkler available with various finishes and temperature ratings to meet design requirements. The special Polyester and Electroless Nickel PTFE (ENT) coatings can be used in decorative applications where colors are desired. In addition, these coatings have been investigated for installation in corrosive environments and are Listed and Approved as indicated in the Approval Chart. As one of Viking's new XT1 models, the VK3501 is more compact for easier installation in tight spaces. All XT1 sprinklers incorporate a stainless steel deflector and an integrated spring and seal assembly that is Teflon® sealed and fully encapsulated to protect the Bellville spring against corrosion. The XT1 spring and seal assembly includes an innovative hinge to help prevent sprinkler components from lodging in the deflector upon activation. XT1 deflectors are corrosion resistant stainless steel, and are laser etched and easy to read for fast model identification.