They certainly appear to fit the Trex however, although I can’t comment on these particular blades, I’d consider you’d need to be very conservative with your headspeed using fibreglass blades generally. After a couple of expensive crashes, I tried a set of fibreglass blades from a reputable well known company on Trex 600E with a 1900RPM headspeed, and after a few weeks found the tracking drifting. On examining them I found that the brass ferrules the head bolts go through were starting to tear through the fibreglass. I’ve seen the result of a 600 sized helicopter shedding a blade in the hover (there was literally nothing left of it – but it was how far away the blade was found that REALLY scared me!) so I scrapped them immediately. Now these may be much better blades for all I know, but if you use them I’d recommend careful checking them after every flight and, if they have a max RPM stated for them don’t ignore it!

Many thanks Keith much appreciated. Carl