Glass fabric laminated with a flame retardant epoxy resin. G-10/FR4 is strong, machinable, moisture resistant, electrically insulating, and flame resistant. This Product is Manufactured in China. Thickness: 1/2"; Thickness Tolerance: (-0.028" - +0.031"); Width: 12"; Width Tolerance: (-0.25" - +0.25"); Length: 12"; Length Tolerance: (-0.25" - +0.25"). Color: Yellow; Clarity: Opaque; Tensile Strength: 38,000 psi; Impact Strength Rating: Excellent. Impact Strength: 14.0 ft.-lbs./in.; Impact Strength Rating: Excellent; Coefficient of Friction: Not Rated; Friction Rating: Not Rated; Water Absorption: 0.0015; Water Absorption Rating: Good. Hardness: Rockwell M110; Density: 0.072 lbs / cu. in.; Temperature Range: 280° F; Specifications Met: UL 94 V0.