Optical sensor base

Three endstops are needed for any 3d printer. Optical sensors can be salvaged from most discarded printers. Wiring has been described in https://capolight.wordpress.com/2010/11/24/making-endstops-from-printer-photo-interrupters/ and elsewhere.
I needed a base which could allow to fit the (standard) 4 legged optical sensor on my Prusa variant, using also the classical clamp on the 8mm rods. Here it is.