This unit blocks hair spray from being sucked into the cooling fins & fan. v.3 has a front deflector with the wings moved in closer. No melt down after several hours of run time. I used 15% density, 3 walls, 3 shell & 3 layer height. Hair spray with crazy glue at the corners. 3 mm holes need to be cleaned and may need modification for a perfect fit. You will need to lay v.3 flat on the build plate. Shield is attached by two short 3 mm screws at the bottom. Start screws & nuts on fan, then push shield into place. You should hear a click. The upper bolts go into the cooling fins. Some Dremal action required.