I bought these for my foot enclosure technology db cromo 12, in June 2012.
I find the clamping my practice I find it also not very strong (the system is a plastic have deserved its aluminum)
Another inconvenience is the small tube will main could be equipped with a end cap instead of the bare tube.
otherwise all is strong and light.
I advise occurs because it is lightweight and low cost are robust carrying case is included.