American Standard Flash Shower Rough-In Valve With PEX Inlets/Universal Outlets for Cold Expansion System - AMS-RU108

No. The RU108 is the rough-in valve body only. The cartridge ships with the trim kit, so you need to order the Flash trim separately to finish the job. What you do get in the box for rough-in work is the flush plug and the plaster guard, which protects the valve and guides the finished wall depth.

It takes 1/2 inch PEX cold expansion inlets to ASTM F1960, with universal outlets. Cold expansion means the F1960 style ring-and-expander system, so you connect straight to the valve with no threaded or sweat adapters, which removes two potential leak points per side.

The rough-in range runs 1-3/4 inch to 2-3/4 inch measured from the finished wall surface to the back of the valve. That one inch of range covers most standard stud-and-board walls plus tile and backer buildup. For a thin wall, the plaster guard can double as mounting support.

Yes, and that is the point of the flush plug. It stays in place of the cartridge so you can flush the lines without cross flow between hot and cold, and you can test with air at 200 psi or water at 300 psi. No need to install and then pull a cartridge just to get through rough-in inspection.

Not necessarily. The Flash RU108 has back-to-back capability, so hot and cold can be reversed quickly at the valve. That is the same feature that lets you serve two bathrooms sharing a wall from mirrored supply runs without re-piping one side.

The body is cast DZR brass, dezincification resistant, which is specified to resist corrosion where chloride levels and pH run high. For a property manager standardizing on one rough-in across a building, that is the material to look for in-wall, since the valve body is the part you cannot get back to without opening the wall.

Yes. The valve has a flat back so it sits flush against a cross brace, which gives you a solid, square mount instead of shimming a curved body. The plaster guard then sets your depth to the finished wall during framing and board work.

Pick by the supply system you are already running. The RU108 is built for F1960 cold expansion PEX, so it belongs on a job where the water distribution is PEX-a with expansion rings. If your building runs copper or you are tying into existing threaded stubs, a cold expansion valve just forces you to add transition fittings, and each fitting is another joint in the wall. Match the valve inlets to the pipe, not the other way around.

A stainless steel retaining ring with flats secures the test cap and later the cartridge. No screws involved. The flats let you get a wrench on it to loosen the ring, which is what makes swapping the test cap out for the cartridge at trim-out a fast job rather than a fiddly one.