Frontline Sliding Beam Anchor - 18 in.* The anchor can be conveniently adjusted from both sides for a secure fit and it's suitable for single user connection. * Aluminum material makes the I beam anchor extremely lightweight * The anchor can be used with either a self retracting lifeline or a shock absorbing lanyard and can fit I beams from 3. 5" wide and adjust up to 18" wide I beams. * Nylon bushings and ball bearings makes the anchor slide smoothly across I beam while trailing the