0.00000000001 g! Seriously though....its tiny. Ill weigh a racquet before and after sometime and post the results. I doubt my scale will even be able to accurately and repeatedly measure it. As for a half a gram throwing someone off......Im not sure of others, but on my end, theres no way I could tell the difference. Of the frames I am using now, 3 are within half a gram of each other and the 4th is the outlier at -3g, and back to back hits would not reveal to my crude sensitivities which is which!