how about you shut the fuck up, and don't post any more threads until you can:
a. learn about a site named "google" G-O-O-G-L-E,
b. use the searchbar and try harder, there are so many different threads on trampolines on here,
c. what the guy above said actually is useful, use the fucking searchbar.
d. have some respect to people who actually know what they're talking about.
study these four steps well, then maybe consider posting again.