you can make it go forward or backward, change the speed as you work, and benefit from a quick change of grinding head thanks to the twist lock chuck. in this case, the proof has to be provided by the guest. it will also show those that took longer to complete of perhaps those that were unable to finish. the good thing is that no matter what jacket is wrapping the speaker core, the audio quality will remain the same. (yes, one of your hotel rooms extends over the pacific ocean!) whether it be a smaller 1200 sq. 