I originally bought the Sagework guitar support with a Standard Arm. For months I was convinced that for my classical guitar position the Standard arm even at its lowest was still a bit too high. I hesitated to return the support because I assumed I had waited too long to make an exchange for the Short model. At last, I found out that the Standard and Short arms are interchangeable, and that I would not have to buy another complete Sagework guitar support, this time the "Short" model. I then ordered the "Short" arm only. With the hex wrench supplied in the original box, I immediately replaced my Standard arm with the Short arm. I have been using the support ever since without the feeling it was too high. It took only a few minutes to replace the arms. And it cost me only $16 + tx/shipping to get the Short arm, not $76 + tx/shipping to buy a second support. The only regret I have is that I did not learn months earlier that the Standard and Short Arms are interchangeable before my initial purchase of the support. I believe I'm a male of average height. If you are over 6', the Standard might suit you. If you are, say, between 5'9"-5'11", you might want to try the Short when initially buying the support. If necessary, you can always buy the Standard Arm as a separate item should the Short feel...well, too short. :-) PS: I'm saving the Standard Arm in the Sagework box--should I suddenly hit a growth spurt...er, yeah, something like that or meet someone who has a Short and needs a Standard. Cheers.