The kinetic theory of sech2x-type electron holes (EHs) is studied. The potential of the EHs is solved in the weak amplitude limit by the pseudo-potential method. We investigate the existence condition of the sech2x EHs. It indicates that the derivatives of trapped and untrapped distributions at the separatrix play significant roles in determining the potential profile. The theory is then applied to the Kappa-distributed plasmas. The amplitude and width of the sech2x EHs are analyzed. Finally, the theoretical results are verified by numerical calculations.