This is a grill for the exhaust door on the P1S (and X1C I assume). It replaces the original door and should be printed in either PETG or ABS as it'll be near the high temperature bed at times. DO NOT PRINT THIS IN PLA.

The idea with this door is to increase air exhaust flow laterally across the printer when the carbon filter is removed and you are using a hose to vent the stench out the window. By default, with the standard door, air will flow from the top/bottom only out of some holes punctured in the top. With the door, the suction area of increased.