I have two questions: I would like to confirm that the weight of fluorescent tubes that I recycled are to be added to total weight calculations used for MR2 although they don't weigh much. I am not certain if they contained mercury and if so, would they be classified as hazardous materials and not used in the calculation? Also, I donated a couple furnaces and a hot water heater to Habitat and assume that I just estimate the weights on these items. Is this correct?