The Heavy Duty Square/Rectangular Manhole features a 3/8″ diamond plate steel cover with rust resistant coating (covers 30″ and larger include a 4″ wide reinforcing channel welded to the underside of the cover), 16 gauge galvanized steel skirt with welded overlapping comers for added strength and carries the H-20 load rating. The 30″ and larger model covers are provided with an easy grip recessed handle. The Model 105LA and Model 105WT are limited access manholes, which include four 3/8″ flush mount stainless steel bolts. The Model 105WT is also a rain tight manhole, which includes a Buna-N gasket. Optional PEMCO Model 105L liners are also available for all models of the heavy duty square/rectangular manhole.