Much lighter than the stock aluminum. and far stronger too! Im not buying the Alum. ones any more. To fit the 450 pro belt, you have to sand some of them down just a bit where they go into the tail, but makes them more secure as well.
I waited 6 months before cancelling an ancient order that was hung up on the booms. Sorry, HK may be affordable (depending on shipping), but one thing HK is not is timely. I wouldn't mind, except that they pretend to be getting stock "any day now" for months and months.
I bought two of this. Pretty light(10.2g), but one is 1mm longer and other one 1mm shorter, than original. Wall thikness is 0.5mm (inner dia. 11mm). Tail unit position hole dia is 2.3mm against originally 3mm.
Bought nine of these, undersized by 1mm, bad aligned hole for the tailsection in a too small diameter and most are cut off crooked. I know they are cheap compared to branded ones, but that doesn't mean they have to be so badly finished. And the 1mm too short could make a difference when you have a torque tube system,(i have one), luckely there stil is a little play between the torque tube and the gears driving it. Be sure to align the hole for the tailsection with the boomblock.
j'ai malheureusement casse ma poutre de queue lors d'un crash severe et j'ai pris une queue en carbone pour une plus grande rigidite ,mais attention ai champ electromagnetique induit par la courroie de queue dans le tube en carbone.