Strong re-enforced frame, fully sealed solid rail extension eliminates deflection, and delivers the smoothest extension movement available, removable 1-5/8" stand-offs reach around braces, top plumb vial permanently positioned at eye level, frame side opposite the stand-offs is a level measuring surface and straight edge, vials are guaranteed for life never to fog, leak or require adjustment. Certified accuracy in the top read position: 1/32" over 72".

Strong re-enforced frame, fully sealed solid rail extension eliminates deflection, and delivers the smoothest extension movement available, removable 1-5/8" stand-offs reach around braces, top plumb vial permanently positioned at eye level, frame side opposite the stand-offs is a level measuring surface and straight edge, vials are guaranteed for life never to fog, leak or require adjustment. Certified accuracy in the top read position: 1/32" over 72".