You can freely change the key number (4-digit number) (listed on the back of the package in the 9th image). The body is brass, and the shackle is stainless steel. The package was cracked, so I took it out and measured the dimensions. The inner width of the U-shaped shackle is approximately 19mm at its maximum, the inner depth is approximately 33mm at its maximum, and the thickness of the shackle is approximately 5mm (please forgive me as I measured with a tape measure). The body dimensions are 40mm wide and 50mm high. Please enlarge the images to see the appearance. It came out of the storage shed (it seems to be from the Showa era). The package is discolored and brittle, and partially cracked, but It is unopened and stapled (please enlarge the image).