This set includes 0.5N, 1N, 2N. 3N, and 5N springs. It can also be used as a supplemental product with the Hooke's Law Apparatus. Springs stretch by 2 cm with a load of 0.5 N, 1 N, 2 N, 3 N, and 5 N, respectively. Each spring has a hook to support a weight hanger and a red indicator arrow.