Installation tips
The height is not adjustable, so be careful to mount it at the correct height. I'd go as far to say you may want to mount it at the right height for your NEXT size speedbag, just to be prepared. (If you are a beginner you will inevitably move to a smaller size bag within a few months). Lastly, make sure when attaching this unit to cinder block walls that you do not overtighten the tapcon screws. Overtightening them is bad, if not worse, than not tightening them (the screw will irreversibly stretch and be less effective). The cinder block wall mounting kit from Ringside is a good deal, you couldn't really get the individual parts (bit and tapcon screws) any cheaper if you bought them at Home Depot or Lowes. Finally, since this is a wall mount unit that when attached right will not vibrate much, you must tighten the swivel with a pipe wrench otherwise you will find that it loosens frequently.

http://www.ringside.com/DETAIL.ASPX?ID=24616