Waist Strap Harness with Belt for the GPX Series This harness increases detecting comfort by attaching your detector to a Minelab generic detecting harness. This harness is supplied with GPX 4800 and GPX 5000 metal detectors. Fits gel cell & li-ion batteries for GPX. Fits up to a 48-50" waist. Minelab Waist Strap Harness with Belt. Waist Strap Harness with Belt for the GPX Series This harness increases detecting comfort by attaching your detector to a Minelab generic detecting harness. This harness is supplied with GPX 4800 and GPX 5000 metal detectors. Fits gel cell & li-ion batteries for GPX. It is also suitable for other Minelab detectors. Fits up to a 48-50" waist.