23 sided prism for turntable calibration

{"cid":"91223678","title":"Precision 23 Sided Prism for Turntable Calibration","imgUrl":"https:\/\/img.chinax.com\/nimg\/12\/7b\/0ed49ccfbbd872c3344a33559343-200x200-1.jpg","attrs":{"Price":"3000~5000 USD","Brand Name":"SPR-ing","Minimum Order Quantity":"1 piece","Delivery Time":"1~3 weeks","Place of Origin":"Shenzhen","Payment Terms":"L\/C,T\/T","Supply Ability":"500\/month","Packaging Details":"Carton","Refractive Index":"1.5","Application":"Optical Experiments","Prism thickness":"17-20mm","Material":"Glass","Flatness of working face":"Grade 0 (Grade II): \u2264 0.03um","Excircle diameter":"\u03c6 80-\u03c6 150mm","Rotating center aperture":"\u03c625mm","Surface roughness of datum plane":"Ra \u2264 0.05 um"}}