A collection of reagents and other associated materials intended to be used for the qualitative and/or (semi-)quantitative detection of total triiodothyronine (TT3) in a clinical specimen within a short period, relative to standard laboratory testing procedures, using an immunochromatographic test (ICT) method [lateral flow test]. This is a rapid test used in the laboratory or in point-of-care analyses to aid in the diagnosis of various thyroid disorders (e.g., hyperthyroidism, thyrotoxicosis). It is not intended to be used for self-testing.