The Extreme RT900 Four-Pin Bow Sight for Compound Bows from Extreme Archery Products features slim-line pins for less target blockage. Total CNC machined 6061-T6 aluminum bar stock construction makes the sight rugged and durable, and more than 2' of ultrabright fiber optics are included. The Tail Light System has been positioned to not only light the tips of the fiber optic pins but to also light the fluorescent centering ring while mounting to the rear for ease of use. A polycarbonate pin guard protects the back of the fiber optics, and a quick-change system makes changing in the field or at home easy without moving the pins. 0.029 stainless-steel pins. 5.25" length. 1.75" housing diameter. 4.7 oz.