1/4" quick-change hex shank - lightning-fast bit swaps, fit impact drivers, extensions * Hard-to-find mini sizes #51, 52, 53, 54, 55, 56, 57, 58, 59, 60 & 61 (0.038" to 0.067") * Durable high-speed steel for cutting power & strength * PVC sleeve to keep bits organized & easy to identify * Great for use with electronics, circuit boards & jewelry items. Average length 2-3/4"