As you are told, the screw standard is M6, not attached. It depends on the thickness of the door because the required size of the screw is different, but if you get the thing, if you do not have the attached screw, I feel it is reasonable price about 50 yen. If I did not change the selling price, I felt that I wanted 2 screws of about 40 mm to be included even if I could not use it (Is it severe in price?).
I wish I had noticed it before purchasing, but the thread was 6φ and it was not suitable for the application. No additional screws are included, and separate purchase is required. It was screwed to a nearby home center and sold cheaper than this, so I will buy it from the next time from the home center.