Sloan #3980189 111 SMO M Regal XL sensor operated closet flushometer.  Standard segment diaphragm, exposed sensor operated, polished chrome plate finish, Regal XL variation, LC closet 1.6 GPF/6.0 LPF.  Metal side mount operator sensor uses 4 - "C" batteries **NOT INCLUDED**  NOS, comes in open factory carton, has never been installed.

For more info & spec sheet go to:

https://www.sloan.com/spec-sheet/3980189