1Made of high quality 304 stainless steel, durable to use, environment-friendly, no pollution, high hardness 2This set is organized by size in a transparent storage case for quick access and protection 3There are 5 different lengths in one set to meet your various needs 4The moderate and clear hex sockets heads can make your working more easily 5Ideal for use by a variety of workers and repairmen from plumbers to assemblymen both professional and amateur, even DIYers can opt to use it