Heavy duty steel construction with rubber coated handle grips. Hole diameter is 5mm ( approx 3/16-inch ) and up to 5/16-inch from edge of card. Capable of handling up to 50 point thick paper of plastic. PLEASE READ: Be sure "In Stock" says: "sold by Oregon Laminations Company". Otherwise, you are not getting an Authentic Oregon Lamination Premium quality Round Hole Punch as listed; however, you can choose the #"new from" link to find the Only True Source of OLP fine Round Hole Punches. - PLEASE do NOT post bad rating for this Round Hole Punch when you purchase from other sellers Piggy-Backing on this listing who must substitute a Round Hole Punch of their choice. This unfairly harms the reputation of these fine OLP Round Hole Punches. Thank you in advance for understanding.