Canadian bred, the Bonar Mark series has made adjustments in their all poly unit that provides enhancement features over the standard all poly design. The Bonar Mark series has a larger support base, more robust top nesting nobs and secure valve area. Though not as dominant as their neighbor from the Cornhusker sate, Bonar has still roto molded a stout counterpart. Its 1/2” wall thickness provides a durable option to the other guy.