ZNB1065 Features: * Short ladder jacks * Recommended for use with 300lb Type IA and 375 lb Type IAA extension ladders (OSHA and ANSI allow use with 250 lb., Type I extension ladders also) * User installed only * Fits round or flat step rungs * Mounts on inner or outer front ladder faced * Lightweight, sturdy, easy to use * Fast adjustments; locks in position * Wing nut lock for quick field adjustment * Packaged in pairs Dimensions: * Accepts stages to 14"" width