EP-NSI is required to use any Hydrophobia rain covers with flagship Nikon DSLR cameras that have screw in eyepieces such as the D4, D3S, D3X, D800, D810, D700 and others.
Hydrophobia 300-600 V2.0
Hydrophobia Flash 70-200
CNC machined Delrin eyepiece with high density foam padding.
No Rhetoric Warranty on all Think Tank products