Constructed of rugged, lightweight polyethylene with bright yellow material that resists fading. Will fit 28″ (71.1 cm), 30″ (76.2 cm) and 32″ (81.2 cm) diameter manholes with an inflatable seal that ensures a watertight seal. Designed with 4-outrigger support gussets that stabilize the shield and is 12″ (30.4 cm) tall to keep water and mud out of manhole as you work. Can be used with Allegro guard rail and shield retainers.