The DeFelsko 200B3-G Positector 200 B3 Advanced Ultrasonic Coating Thickness Gages for Non-Metal Substrates, 0.5 - 40 mils is DeFelsko PosiTector 200B3-G non-destructively measures a wide variety of applications using proven ultrasound technology. The DeFelsko 200B3-G Positector 200 B3 Advanced Ultrasonic Coating Thickness Gages for Non-Metal Substrates, 0.5 - 40 mils is PosiTector 200B3-G model measures polymer coating on wood, plastic, etc. Advanced models of The DeFelsko 200B3-G Positector 200 B3 Advanced Ultrasonic Coating Thickness Gages for Non-Metal Substrates, 0.5 - 40 mils is PosiTector 200 measure up to 3 layers with graphics.