The 3490-25 ball prism is a stainless steel ball prism of 1.5” (38.1 mm) with a 25.4mm glass triple prism. The Prism constant is K = -16.9 (Swiss-style K= +17.5) mm. This diameter of 1.5“ (38.1 mm), is based on reflector balls from laser tracking applications. The ball prism monitoring system thus enables highly accurate tachymetric precision measurements (bases are sold separately.)
– Shockproof and waterproof
– Visible prism center
Return: 14 days money back or replacement buyer pays return shipping 20% restocking fee may apply
