These sights are designed for even the fastest bows. They have a unique double row of clear Lexan blocks that are machined completely from billet stock. They are designed to gather as much light as possible. Although Tru-Glo fibres need little light to perform, we gave them as much as we could. The rest of this durable sight is machined from 6061-T6. All aspects of this sight are machined! The angles to insure the proper fit and alignment time after time, right down to the slots the sight pins travel in. No short cuts were taken on this sight. Each sight comes with a receiver to mount on bow along with a full instruction and assembly sheet.