G.F. Sprague is Wellesley Hills, Ma's replacement window contractor. Whether you have aluminum windows, or vinyl windows, we have the replacement window solution for you. All of our work is backed up with a 40 year handiwork service warranty. You have confidence with GF Sprague with all your work for replacement windows. G.F. Sprague has actually been around given that 1969 and has more than 10,000 satisfied customers.