Photo Interrupter GP1A57HRJ to mount on a MicroRax beam profilePhoto Interrupter GP1A57HRJ to mount on a MicroRax beam profile. This is a direct re-make of the SparkFun board which can be found here: http://www.sparkfun.com/products/9322Note the lack of mounting holes.All components and planes are clear from the mounting holes and from the MicroRax beam. The screw holes are sized and spaced to bolt directly to a beam with the 2-hole nut plates for the beams. Of course MicroRax not required, feel free to mount to whatever you likeProduct Link: http://www.batchpcb.com/index.php/Products/73267