The Think Tank EP-N eyepiece is required to use any Hydrophobia rain cover with Nikon cameras featuring slide-in style eyepieces only, as well as the Pentax K10D. The EP-N is compatible with the Hydrophobia 300-600 V2.0, Hydrophobia 70-200 and Hydrophobia Flash 70-200.

Compatible Hydrophobia Rain Covers:
Hydrophobia 300-600 V2.0
Hydrophobia 70-200
Hydrophobia Flash 70-200

Compatible DSLR Cameras:

Nikon
D40
D60
D3000
D3100
D5000
D90
D300
D300s
D7000

Pentax
Pentax K10D