The 13367 is a replacement sensor head for the HMP45C temperature and RH sensor. While in the field, you can use the 13367 to replace an HMP45C's sensor head without disconnecting any sensor wires.
This product was formerly ordered as the HMP41. When Vaisala sells a complete probe, the head is labeled HMP45AC. When Vaisala sells the head only, the head is labeled HMP45ASP.