Vendor product code TSRED76.  The full name in the product website heading is "TS-Optics 0.82x field of view corrector/reducer for 76mm f 5.5 Triplet APO", which is long-winded indeed but could end being the best option.  It is later referred to on the very same site as "TS-Optics 0.82x Reducer for TS76EDPH"; which is disingenous, as a "TS-Optics 76 mm f/5.5 Triplet Apochromatic Refractor" (code TSAPO76) plus this reducer/flattener (TSRED76) do make an "TS-Optics 76EDPH - 6-element Flatfield Apo 76 mm aperture F/4.5" (code TS76EDPH).  So an unambiguous and truthful name could  be "0.82x Reducer for making a TS76EDPH out of a TSAPO76"; but I hesitate to make such a proposal.