It is not useless. Its open on the other end so the starter motor will fit through it. Once fitted to turbine no foreign material can enter turbine intake making this product perfect. If you see all other genuine screens they are all open at both ends and cost up to 6 times the price.
Hi. The inner ring is not made of rubber. You'll have to find a way to secure the FOD to the starter motor. I used a little rubber ring that I had in the workshop. There's very little vibration from the turbine motor, so securing the FOD should be easy.
the 110mm would fit the 80 to 160 class jetcats the 98mm is for the 70 jetcat and maybe the new 100 coming soon and the 90mm would be for the 60 jetcat this is all taken from the fod screens i have on my turbines now that look identical to these hope this helps
Do I smell kerosene? It would be great if HK could bring in turbine engines like Kingtech, made in Taiwan, that is reasonably priced compared with those made in Germany. I would definately consider buying them.