I just attended a Train the Trainer session for the Bone injection gun by Waismed. I'm more familiar with EZ-IO and the FAST ONE. The B.I.G. doesn't seem to me that it's all that adjustable. Essentially, it's spring loaded and just pounds through the bone into the marrow, yet there is no way to continue pushing the needle through if the spring doesn't get it all the way to the marrow.