Customized Stress Relievers, Acorn - Stress Reliever - Polyurethane, Acorn shaped stress reliever, 2" diameter x 2 5/8". Due to their handcrafted nature, stress ball sizes, colors and textures may vary. Factory cannot guarantee consistent imprints or PMS matches. Material: Polyurethane. ... #LNA-AC01 $2.51/each.