With ordinary nail sets and center punches, you have to focus on holding the tool and striking it squarely. Not with these.
Each consists of two pieces of turned, hardened steel joined by a tightly coiled spring. Just position one tip on the work, draw back the other, then release.
The brad set has a 1/16" diameter center pin for driving 3/32" brads below the wood surface or for marking hole centers for hinges. The prick/ center punch has two conical tips with different included angles — the 75° end makes a shallow mark during layout, and the 45° tip makes a deeper dimple to prevent drill bits from skating.
Especially useful where you don't have room to swing a hammer, the combination nail starter/set has a 1/8" diameter recessed tip that fits over a finishing nail to drive it shy of the surface, and a cupped tip to set it. The double-ended nail sets have concave tips to register the tool on the head of a finishing nail.
Ribbed for grip, all are hardened to Rc59 and measure 4-1/4" to 5-1/4" overall.