Step it up a notch, with an extra firm compression corset. The 9 Flexi Steel Boned Aggressive Black Core Trainer is a latex and cotton corset work out band. This is one of our aggressive core trainer for the serious waist trainer. Wear at the gym, during work outs or day to day. Compared to our basic Core Trainer that has 4 rods of boning, this compression band has 9 rods of boning making the fit of this trainer a little more firmer.