On Brendle's Estimate for the Inscribed Radius under Mean Curvature Flow

In a recent paper [3], Brendle proved that the inscribed radius of closed embedded mean convex hypersurfaces moving by mean curvature flow is at least 1/(1+δ)H at all points with H≥C(δ,M₀). In this note, we give a shorter proof of Brendle's estimate, and of a more general result for α-Andrews flows, based on our recent estimates from Haslhofer and Kleiner [4].