#58 Main Burner Orifice - Propane Units. The thread for this part is 8MM Fine thread.

This part is also known as: N455-0038, NAPN455-0038, B0FDX1RFQL

Does your part fit?

Many replacement parts look correct but won’t fit your model. This grill part fits the following models:

Napoleon:
PT750RSBI, PF600, PF450