American Standard Aerator 55/64-27Uns-2B 1.8Gpm - AMS-M922911

The thread is 55/64-27 UNS-2B. The 2B class designation means it is an internal (female) thread, so it threads over the male outside threads of the spout tip rather than into it. 55/64-27 is the common male-spout size on North American kitchen and lavatory faucets, so if your spout has exterior threads at that size this aerator will land on them. If your spout is threaded on the inside instead, you need a male-thread aerator, not this one.

Rated at 1.8 GPM. That is a water-conserving rate below the older 2.2 GPM standard, so swapping a 2.2 GPM aerator for this one cuts flow at that fixture without touching the valve or supply lines. For multi-family or hospitality retrofits where you are standardizing fixtures on a lower flow, the aerator is usually the cheapest point to make that change.

It is a faucet aerator. The application is faucet spouts only, and the 55/64-27 thread is a spout thread, not a shower arm thread. Shower flow restrictors are a separate part and do not interchange with this.

Usually, yes. A clogged or scaled aerator screen is the most common cause of a weak or split stream on an otherwise working faucet, and it is the first thing to replace before suspecting the cartridge or supply stop. This is a complete 1.8 GPM aerator assembly, so you unthread the old one off the spout and thread this one on in its place. Confirm your spout takes a 55/64-27 female-thread aerator first.

It is supplied in stainless steel. On most spouts only the outer rim of the aerator housing shows below the spout tip, so the stainless face reads as a neutral metal edge rather than matching a polished chrome or brushed nickel faucet exactly. Order code is M922911-0750A.

Order by manufacturer part number M922911-0750A. That is the stainless steel, 1.8 GPM, 55/64-27 UNS-2B aerator. Distributors should quote that full number including the -0750A suffix, since the base number alone does not pin the finish.

Most aerators of this type thread on hand tight, and hand tight plus a light snug with a cloth-wrapped pliers is enough. No plumbing disconnection is involved, since the aerator threads onto the outside of the spout tip at 55/64-27. Turn the water off at the faucet handle only, not the supply stops.