This is a dense latex sponge. Comes in 3 sizes.

Most commonly used for:
Bald Cap
Tattoo Cover
Prosthetics Makeup
Injury Simulation

Small - Dimensions: 1 3/4" x 1 1/2" x 1 1/4"
Medium - Dimensions: 4 1/2" x 2 1/2" x 1 1/2"
Large - Dimensions: 5 1/2" x 4 1/2" x 1 1/2"