Toque pillbox 3-piece break apart block. Head size noted at 22 inches. Shape will easily accommodate headsizes up to 23 1/2 inches. Height of shape at front 5 inches, 3 1/2 inches at back and sides are 5 inches. Front to back width is approximately 7 inches and side to side width is 9 inches. Circumference at the top of the shape is 25 inches and bottom is 24.
Short video of the hat block on a mannequin head to show the shape - https://photos.app.goo.gl/LOWHwDrOhHDId6de2