Types 40L and 40S feature the same robust, Balanced, ‘O’-Ring Mounted, set-screw driven, Rotary unit as described on the preceding Page. The Type 40 Rotary can be used with a wide variety of Stationary Seat Rings depending on the dimensions of the equipment the Seal is to be fitted to. The most widely utilized stationaries are the ‘O’-Ring Mounted Type 24 to suit metric DIN housing sizes. For convenience Vulcan stock these combinations as Type 40L with a 24 DIN LONG with anti-rotation pin provision. Or as Type 40S with a 24 DIN SHORT Seat without such pin drive provision.