These two OEM supplied blue O-rings fit ONLY the battery door of the Shearwater Perdix AND Petrel dive computer models. The Perdix battery door requires two O-rings and the Petrel battery door requires one O-ring. If you dive the Perdix or Petrel then we strongly suggest you keep a pair of these in your save-a-dive kit.

Note: These O-rings are nitrile 112 size, 70 durometer, the same as the O-ring size used on most DIN regulator fittings.