Both sides open. Energy efficient insulated exterior double door unit. Completely assembled in primed wood frame, with full weatherstrippping and fixed sill. Insulated 22" x 64" glass inserts with raise/lower/tilt mini blinds between the glass panes. Primed; ready to paint. Unit measures approximately 71-3/4" x 79-1/2". Viewing from the outside, the main operating door is on the left.