I reviewed a set of Bushnell Marine 7X50mm binos here:

Review: Bushnell Marine 7X50 Binoculars for Law Enforcement Use | ThinBlueFlorida.com

In doing some research, I found that the 7X50's are referred to as "night glasses." Wasn't sure why until I looked into it, but they do work extremely well for surveillance in low light conditions.