A concealed hook component, that when used in conjunction with RP32, forms an interlocking threshold for outswinging emergency exits and provides security. Location Door bottoms. Seal Sizes Available in stock lengths. Maximum length 3000mm. Standard Finish Anodised Satin Clear or Bronze. Fixing Method Zinc plated, cross recess head countersunk S.T. screws of the appropriate size and colour are supplied. Used in conjunction RP32 Threshold plate.