This hammer extension slips over the existing hammer to make hard to reach or hard to cock hammers easier to use - a must for scoped guns with external hammers. It is made of blued steel with a knurled surface for easy gripping. Allen wrench included. Fits most hammer type guns, either right or left side. No low wall or high wall designs. This item fits all Marlin lever actions made in 1983 or later (including 39A, 39M, 1984, 1984C, 1985S, 336C, 336T, 375, 444S, Glenfield 30A).