The JM Press is a hybrid, a monster. Adding chains and doing it with a far bar, like Dave does in this video, is akin to creating a weight room Frankenstein. This mutant exercise gets it done though. This movement is a version of the standard JM Press. If you aren't familiar with the JM Press, I suggest you learn it before attempting a modified version such as this. The floor may limit the range of motion a little, but that's the point. The chains will make the lockout much more difficult, which is also the point. This is a great exercise to improve lockout power and general awesomeness.