It has an acorn dorwal handle set.
Patio door handle broken.
You also might want to add or replace a keylock on the outside so you can open your patio door with a door key.
Prime line c 1225 sliding patio door handle set replace old or damaged door handles quickly and easily white diecast mortise style non keyed fits 3 15 16 hole spacing.
My patio door is about 27 years old.
In addition to patio door handles handles there are other bits and pieces that often need replacing on patio doors.
You should find a few screws around the edge of the handle which need to be unscrewed or you may have a screw on the edge of the door frame.
The inside piece of the handle holder has broken in half at one of the screw holes.
The fix clips that hold the panels in place often get broken or get lost.
The number on the inside piece is l 120.