Ball Prism - 1.5″ (38.1mm) Diameter w/Kanten BaseThe ball prism is a precisely manufactured steel ball with a triple prism reflective foil mounted very precisely in the center of the ball. Economic monitoring of points by means of automated target detection Cost effective solutions through the use of centering plates Very high repetition accuracy due to forced centering Ball prism 1. 5" (38. 1 mm) Material of the ball: Galvanized steel (also available in stainless steel) Steel sphere: 1. 5: 0,05 mm