OPT has served Astronomers and photographers since 1947. Today, we are the world’s largest online astronomy and astrophotography equipment store. Our warehouse stores an extensive inventory of used gear so we meet nearly every need.With over 70 years of experience in buying and selling used equipment, our customers trust in our inspection process. You can rely on our expertise and excellent customer service because each used product is tested by our technicians for full functionality before they are taken in on trade. You can buy with confidence because all of our used equipment is guaranteed to work, regardless of its cosmetic condition, and come with a 90-day Parts and Labor warranty.