For p ∈ [0, 1], the generalized Seiffertmean of two positive numbers a and b is defined by Sp(a, b) = p(a-b)/ arctan[2p(a-b)/(a+b)], 0 < p ≤ 1, a ≠ b; (a+b)/2, p = 0, a ≠ b; a, a = b. In this paper, we find the greatest value α and least value β such that the double inequality Sα(a, b) < T(a, b) < Sβ(a, b) holds for all a, b > 0 with a ≠ b, and give new bounds for the complete elliptic integrals of the second kind. Here, T(a, b) = (2/π)∫ Due to image rights restrictions, multiple line equation(s) cannot be graphically displayed.√a²cos²θ + b²sin²θdθ denotes the Toader mean of two positive numbers a and b. [ABSTRACT FROM AUTHOR]