A solid 2306 option for 6S.
This motor is marketed from OAS Hobby as a sleek, simple, and inexpensive 6S race motor, which is an accurate description. Construction was hard to measure since the set screw stripped out once it was half removed. They spec a 1.5mm buttonhead screw and some seriously tough thread locker. I've since learned that you can melt the thread locking compound if you first heat it with a soldering iron, but alas, too late. This isn't a dealbreaker for those who would rather replace a damaged motor than fix it, but I wouldn't reliably expect to be able to disassemble it to replace bearings or bells. The shaft is hollow titainum, and the bearings are reported as 4x8x3 mm. There is a little raised textured shelf for the prop to sit on, which should help prevent ESC or Motor wire Prop strikes on a motor that's relatively shorter than 2207 offerings in the same class. The texture should also give some help with loosening prop nuts on CCW motors.
Performance - wise, the Black Ops fits in nicely with other offerings. It weighs only half a gram more than the T-MotorF40 Pro II 2306 1600kv, but makes ~100g more thrust (with the same response time) at the cost of 3-4 amps at full throttle. The Black Ops makes about the same thrust at max throttle as the Catalyst HV Revolution 2306 1725KV, but with about an amp lower current draw. The Black Ops weighs in at a gram more, likely due to more durable design choices.
All in all, this motor would fit well into a light racing rig with thoughts toward power and efficiency. It's not the most powerful motor in its class, but will make a good amount of thrust while maintaining efficiency for smaller battery packs.