Lockwood 3573 half cupboard sliding door lock 

This lock has a turn on the outside and nothing on the inside, its used to keep the door from sliding open, the 184 pull handle allows for easy access to use this handle a plate with exposed holes is required on both sides, the lockwood 1906 and 1907 plates allow the handle to be used.
Outside: Turn operates bolt.
Inside: No function, blank plate.