This is an OTIS OEM brushed stainless steel luxury micro motion III pushbutton. The target profile is flat projecting, it is a yellow/green LED, 24 volt button with an AMP four position connector, and clear front ring body also known as halo or light ring. The marking on the button will show AAA CH10, or AAA AK21. Previous or alternative part number is AAA23500AK21 Please note the locking nut, also known as the retaining ring FAA72N1, is not included with the button. Parts may only be used and installed by certified licensed technicians