The Lidar-Lite from PulsedLight is neat widget, but I found my unit sprays quite a bit of IR outside of the main axis of the collimated laser beam; some internal scattering maybe. As a consequence, a nearby surface can be detected by scattered illumination, even when it is not on-axis. Also, it wouldn't hurt the receiver to have a sun-shade in place, so I designed this. Wall thickness is 0.8 mm and with a 0.4mm print head, it works best if you set infill to 0%. OpenSCAD model included.UPDATE: v4 has more baffles (# of rings is a parameter), tighter ID of baffle rings, and improved mechanical fit to Lidar case.Note that many plastics are translucent at 900 nm, and in fact I could see the beam through the wall with an IR camera before I painted it. For this to work as intended, you need to paint the inside with an opaque flat black paint ( I used "Angelus Brand Acrylic Leather Paint".) This can be tricky to apply given the internal baffle rings, but an old toothbrush worked nicely.