The Klinch-Pak KP-APN pneumatic carton closing clinch stapler drives A Series 1-3/8-inch crown carton staples from 5/8-inch to 3/4-inch in length. This industrial grade carton stapler features a lightweight, well-balanced, and ergonomic design. All Klinch-Pack series carton staplers feature separate adjustments for depth of penetration and tightness of clinch. The KP-APN is excellent for folding boxes, complete overlap, and other corrugated cardboard applications.