A large-scale model was used to study the magnetization distribution in an isolated transition by measuring the stray fields near the top and bottom surfaces of the medium with a small Hall probe. It was found that, in an unoriented γFe2O3medium, more flux escapes from the top than from the bottom surface. A simple, four-parameter transition function was found which is consistent with the observed stray-field distribution; Mx(x) is an arctan function, whereas My(x) is an arctan derivative. Expressions for Hxand Hy, inside and outside the medium, were derived and values for the four parameters were calculated by a least-squares fit to 28 experimental points. In a thin, square-loop medium with high saturation magnetization, the isolated transition has a pronounced asymmetry and Myis either zero or an odd function of y.