1.25"L x .875"W x .625"H
The Accuracy 1st illuminator is well built and functions as advertised. Sadly the unit adds so much bulk to the back of the scope level that I could find no way to successfully mount it to any of my rifles. I'm going to hang on to it and find a setup that works. I would give it another star, but it really is a shame the batteries aren't replaceable. The service from Bison Tactical was great, no complaints!