Keyes Cutaneous Punch, Sklar. 4 in., 6mm, Sharp, Straight, Fenestrated, Knurled, Stainless Steel. Merit Keyes Cutaneous Punch are used to collect a sample of tissue for biopsy. The punch is available in 2mm-6mm tips. Merit instruments are Sklars office-grade line of products and most commonly utilized for routine and in-office minor procedures.