Polypropylene is an economical material with moderate resistance to water and chemicals. Shape: Ball; Material: Polypropylene; Grade: Standard. Diameter: 3/8". Color: White; Clarity: Semi-Clear; Tensile Strength: 4,200 psi; Tensile Strength Rating: Poor; Impact Strength: 1.2 ft.-lbs/in.; Impact Strength Rating: Poor. Coefficient of Friction: 0.5; Friction Rating: Slippery; Water Absorption: 0.0001; Water Absorption Rating: Excellent; Density: 0.033 lbs / cu. in.. Hardness: Rockwell M85; Temperature Range: 0° to 180° F.