This is The Binotron 27 Ala Carte. It has no Power Switch, No OCS. It comes with a case and a 2" Nosepiece. It is the proper Binotron -27 to add to an S2 or R1 Power Switch Star Diaognal.  See additional info on those Denkmeier Power Switch Star Diagonals.
 
Note:This Binotron 27 version will not reach focus without an R1 Diagonal in a refractor unless that refractor has a special shortened tube and is binoviewer-friendly and can accomodate a binoviewer with 118mm of back focus requirement. It will not reach focus in a Newtonian Telescope.