Dan is right on depth but the operation of the coil depends on what machine you are using it on. Some units will detect the full length in AM and others, just the front half of the coil. Jimmy no longer sells the BigFoot due to the death of the manufacture, but he should be able to answer your questions. Weight is no problem, a very lightweight coil and a breeze to use........ ideal for covering large areas like beaches and sport fields for clad and jewelry. I haven't used a Bigfoot on the IDX so you may very well get the half coil in All Metal. On the DFX and V3i, I get full length in All Metal mode, but either way it pinpoints spot on between the arrows.