Viking Specific Application window sprinklers are quick response glass bulb, automatic sprinklers. Both Pendent Vertical Sidewall (VSW) and Horizontal Sidewall (HSW) versions are available to meet design needs. 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/approved as indicated in the Approval Charts.