G.F. Sprague is Wellesley Ma's replacement window contractor. Whether you have aluminum windows, or vinyl windows, we have the replacement window solution for you. All our work is backed up with a 40 year craftsmanship guarantee. So you have confidence with GF Sprague with all your work for replacement windows. G.F. Sprague has been in company considering that 1969 and has more than 10,000 pleased consumers.