The Grass P15 A.C. Preamplifier Model P15B is a high-quality preamplifier designed and manufactured by Grass Instruments in the United States. This model is specifically labeled as the P15 Rev B, indicating a specific revision or version of the product. Known for their expertise in medical and lab equipment, Grass Instruments ensures that this preamplifier is reliable and suitable for various applications in the healthcare and industrial sectors. With a focus on precision and performance, the Grass P15 A.C. Preamplifier Model P15B is a top choice for those seeking quality equipment for their labs or medical facilities.