Most every one of us can read a box as well as the people in a hobby shop but they are just stating what HT printed. How much carbon fiber is added to the gears to make them four times stronger?? What does stronger mean and how is it tested? I use HT servos, I like them a lot but even today there is no warning about the type of use for these servos or a warning about when not to use them. I have a box full of the 6985s I bought on a close out sale, super deal but they shouldn't be used in the planes I bought them for. It took a number of years before I ever read any warnings about them. I did break a couple of gear trains but it was from an RF flutter so I never gave it any thought. I saved the plane so therre was nothing lost. I did try to get a new brass gear set for them but they didn't make a replacement set for these servos. It may be worth my time to check again because the 6985s are very good but have there limits because of the gears. Karbonite gears may be four times stronger then nylon but nylons don't snap because they are brittle, they will strip but it takes a bunch to do it.