Sunday Optics is making various prisms, right angle prisms, penta angle prism, roof prisms, wedge prisms, dove prisms, porro prisms Material: BK7 K9 JGS1 Sapphire ZnSe Germanium Silicon Size:0.5-600mm Angle tolerance:+/-1 seconds Surface Quality:20/10 Flatness:1/10lambda. Coating: Al, Silver, Gold,HR,Dielectric.