I bought a Williams aparature rear sight for my '09 Benjamin 397. With it set as low as it would go I was still shooting high (a common problem with the Williams sight). I didn't want to grind off the bottom of my new rear sight so I made a new taller front sight. Next, I wanted to be able to adjust the elevation without using a screwdriver so I made a brass thumbscrew. Finally, I didn't like the big hole in the aparature that came with the sight. It's fine for plinkin', but a little big for target shootin'. I made a brass aparature with a .055 hole, the original has a .095 hole.