Cover cap for M6 and M10 nuts with tee You can use it for just a nut too, just flip the model upside down and lower it under the bed down to the nut part

Edit 08.IV.2019 For different nut sizes just resize it in slicer.

Edit 15.VIII.2023 Uploaded M6 and M10 nut caps Files are with proper names now and with lower disc space usage