In most seated positions, the ToneWoodAmp has no contact with your body.                                                                           (Note: TWA in picture is our prototype - your device will be smaller in size). 

In terms of weight, there is virtually no impact on your experience. The unit weighs just under 8oz., it is through our experience that the only way you will notice the ToneWoodAmp is attached to your guitar - is by turning it on and hearing it sing ;).