We fit this type of valve to all our "Clubman" range locomotives - running at 120pi working pressure - as well as replacements for secondhand engines that come in which have safety valves that either don't open or shut reliably, or accumulate (or all of the above if you're unlucky).
Supplied assembled, complete with hex key for the locking screw. The valve will require setting to the required working pressure before use.
Includes free UK post and packing.