While the holder was destined for the wall I also wanted to be able to place it flat on the table, which is why I chose to mount it using rails on either side - they allow the holder to slide in&out freely. Relative to the front face the bits are held at a 40 degree angle which means they are held in place when the holder is in either orientation but it also keeps the overhangs on the safer side of 45 degrees for printing.