This vintage set of weights from Ainsworth's Class S line is a must-have for collectors and enthusiasts of medical and lab equipment. Made in the United States, these calibration weights are a rare find and come in their original box. The brand's reputation for quality and precision in measuring equipment is well-deserved, making this set a valuable addition to any collection. The set includes a variety of weights, all meticulously crafted and marked with the Class S model. These weights were designed for use in medical and lab equipment, making them a unique and valuable find for collectors. Whether you're a seasoned collector or just starting out, this vintage Ainsworth Class S set of weights is sure to impress.