This is a cloth hanging shelf pipe joint. This is a adjustable elbow joint for the pipe. You can use it other purpose too. Pipe diameter should be 25-25.4 mm. 3d printable stl file attached. 3d editable STEP file formats also attached. Metalic materials will be best for print this.
Custom size and design possible. You have to contact with me for more details.
Thanks, Mahbub