With K-factor of 25.2 (363), Model VK598 Standard Response Upright Sprinkler is approved for use in both dry and pre-action systems. Unit can protect Class I-III commodities with storage heights up to 40 ft in warehouses as high as 45 ft, without need for additional in-rack sprinklers. Featuring 1 in. NPT thread size, VK598 is FM-approved for protection of open frame rack, solid piled, palletized, and bin box storage configurations, with maximum sprinkler spacing of 10 x 10 ft.