Leeper's Z-Nailers up the ante in modern clean-aid climbing. The Z-nailers will often seat perfectly by themselves in pin scars. Stack the Zs with other standard pins for wider bashed-out cracks. The location of the sling holes are key in creating a stable placement. More often than not the sling will be in the crack pulling straight down. This does wonders in reducing leverage and keeping your pro in the crack.