This is the lightweight (4 oz.) mallet we use with our SmoothSet tube-setting punches for setting gemstones. (This is the hammer that's pictured in the shop's lead photo along with a SmoothSet.)One face is nylon (helpful for tapping stones into position) and the other is brass – good for light strikes on the the tempered steel punches. This two-in-one mallet keeps both faces always at hand! The faces are replaceable – just loosen the collet (the little wrench that's included may help, or use your fingers) and the face pops right out. For replacement faces, see our other listings. Brass replacement:https://www.etsystudio.com/listing/387453308/brass-replacement-face-for-smoothset?ref=shop_home_active_4Also included is a face that's labeled as "fiber" – we don't use that one, but you may find it useful in your projects.