Deltana SDRP218 Sliding Door Round Passage Lock (2-1/8")

2-3/8 inches. The SDRP218 is a fixed 2-3/8 inch backset, which is the shallower of the two standard residential backsets, so mark the strike and edge prep to that dimension. If the pocket door already has a 2-3/4 inch prep, this one will not line up. Where you need flexibility, the Weslock 0627 round passage pocket door lock is an adjustable backset version of the same round trim idea.

It does not lock. The SDRP218 is a passage function, meant for a hall, closet, or pantry pocket door where you only need to pull the door shut and latch it. If you need a bathroom or bedroom pocket door that locks from inside, look at a privacy version instead, such as the Orca Hardware PDLRD round pocket door lock or the Weslock 0577 rectangular privacy pocket door lock.

2-1/8 inches. That is a small round face, so it sits neatly on a narrow pocket door stile and leaves less patching if you are covering an old cut-out that was itself round. Rectangular pocket trims run much larger, for comparison the Emtek 2101 passage pocket door lock is 2-3/8 by 3-1/8 inches, so if you are trying to hide a bigger existing mortise the round 2-1/8 face will not cover it.

It is a residential-duty pocket door lock. For apartments, condos, single family, and light hospitality guest rooms it is the right class of part. For a high-traffic commercial opening you want a heavier pocket door latch, the Rockwood 891 pocket door privacy latch is the commercial-grade style of part in that role.

No handing to specify. The SDRP218 is a round passage pocket door lock, symmetrical trim on a 2-3/8 inch backset, so it works whether the pocket is on the left or the right. You order it by finish only.