International Divers of Montreal Canada made direct copies of US Divers regulators. This single stage was a Mistral copy. It retailed for $60.00 in 1958. This model was located by the museum staff near the Toronto area. The hoses were perished so new reproductions were placed on the reg. This model did not use a duckbill instead opting for a one way valve lodged in the exhalation hose.