Optima Prism (All Metal) - 63-1010V Optima All-Metal Prism Premium Series 0/30mm Constant Prism System. All metal holder and target warranted for life. Fully compatible with leading manufacturers such as Sokkia, Topcon, Pentax, Nikon, etc. Hermetically sealed (2-1/2") Precise Prism. Tension adjusting brass knob. Brass 5/8x11 bayonet adapter. Yellow/black