Adjustable recoil pad.
This can be a really effective alteration for shooters with high cheek bones or long necks. The standard stock profile can cause the neck to be held compressed and uncomfortable or for the sole of the butt to be too high in the shoulder. This little fitment allows the recoil pad to be lowered allowing the shooter to maintain the correct contact between the comb and cheek bone, while also allowing a more upright and comfortable stance with the correct contact in the shoulder pocket.
See How this shooter has the perfect contact at the cheekbone with a comfortable neck angle, and the adjustable recoil pad fitment has allowed the recoil pad to be in this shooters preferd location an inch below the top line of the shoulder.