This is how I do 21s rather than the conventional version. The pump is insane. The growth is even better.
[video=youtube;9L_03MkhNn8]http://www.youtube.com/watch?v=9L_03MkhNn8[/video]
[video=youtube;9L_03MkhNn8]http://www.youtube.com/watch?v=9L_03MkhNn8[/video]