Got this in email from a recent Katana customer-
Below is a review for the Katanas:
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As an NVG Instructor, I appreciate good tubes.
These are off the charts, in all aspects. Weight. Balance. Clarity. Brightness. Auto Gain. These are the lightest dual tubes I have worn.
Having had these tubes for a month, and 40-50 hours on them already, I have not had a single issue. These. Just. Work.
While Phosphorus - I have always used green tubes. These WP tubes are next level fantastic.
Battery Life - I am surprised at how long a single 123 battery will last, in these. I know I got 30 hours of run time, out of one batt, and know it would have gone longer, if I hadn't broken two rules: 1. Always pull your battery after you are done using, for the night. 2. Always check your tubes to see if they are on, and you missed Rule 1, before you put them back in the box.(Instructor Note: always put your investment back in the box, when you aren't wearing them, and always, always protect your glass!)
I am new to the concept of lifting your tubes away, individually, instead of folding the package up. This is a life changer. Lots of clever little reasons why you will want this in your world. After ten hrs, it becomes as natural as walking. You can fold them up, still, but you won't need to...
Handy tips:
Set the mount as far from your face as possible - you get better peripheral that way.
If you are new to dual tubes, purchase, or make, a small counterweight pouch for the back of your helmet. Yes, i said that these tubes were amazingly light, but everything needs balance. As you strengthen your neck, the counter balance will help - also a good spot to store an extra 123 batt, or two...
Function tip - when using the Lo-Sto mount, you need to unscrew a small block, at the lower, aft area of the mount. Five small screws, with tension springs, and a set pin come out (keep them, and the block, in a baggie) this block is for a different mount, but needs to come off, for use with the dovetail of the Katanas (zero issue - can't hurt it).
Use the bungee cords on your helmet! There are two tiny rings on the aft portion of the assembly block, on the goggles. Hook the bungees to these rings. Bungees are cheap, the locking mechanism works good, but goggles are expensive...
Good hunting...
Joe B.