This set contains 20 pieces of the seven dissection instruments, 100 blade #22's for the #4 scalpels, and 300 t-pins for pinning back specimens during dissection. Classroom set is ideal for a classroom of 20-40 students; classrooms with more than 20 can have their students work in pairs. All tools are constructed of premium stainless steel unless otherwise noted. The classroom dissection set comes in a medium-large sized plastic tray with 6 compartments that provide easy and safe storage of the tools for later use.