The B. N. Yanow Co.is proud to announce 50 years in business. Headquartered in Braintree, Mass., and incorporated in 1948, the agency is a large marketing and sales group for construction products in the electrical industry. The company now employs more than 40 people in four separate divisions and has five non-stocking branches located in Massachusetts, Rhode Island, Maine and Connecticut. Founded by Bernard N. Yanow, the company is now owned by Alyn Pinkofsky, who joined the company in 1961 as a sales representative. His son Randy, who has been with the firm since 1980, was elected president of the company last year.