I used these engine mounts to ride a quad 330mm with 1500KV motors, propellers 8 inches, and work well under normal conditions.
The only problem is that not stand a fall, because they start very easily.
I do not advise the use of these supports for quads race or acrobatic.Weak and soft, don't waste your money, the side supports are very small and thin (see the stock photo) and aren't able to keep the mount level except with the smallest of motors (under 30 gram) which is not what this was designed for. Plastic is a soft pliable ABS, not suitable for this type of mount.Part is OK but only for Motors under 100W or whight under 35g.
The holder is to flexible for motors with a lot off power.
I have used on my hexa with SK3 2830 1130kv an 58g with 187W and prop was not balanced and the holder are brocken!
For litle motors it is perfekt! Please HK write this!