Here three solution to mount the PIR sensor model MR-HW06A or MR-HW06A:

-in 503 plaque adapter wall mount

-up-down box

-in rotating box + - 25° angle (thanx to @DieZopfe remixet ball joynt)

choose your favorite solution and print it with no particular indications!

NOTE: for up\down version I suggest you to use a couple of 1mm washers