I don't know about you but I'm sick of those magnetic bit holders leaving my mini bit in the previous screw. The Insty racquet holds the racquet in place.It also holds "regular" bits/hex shank tools (wish I knew the technical names of these two bit shank standards - that would make me sound more professional).The Insty short bit has a hex shank and requires hence a ratchet chuck (serrated or hand-tight). The 4" Insty Bit has a long, quick-change shank design, so it also fits directly into the drill chuck. As a tool, you can put a 4" drill chuck in the short model. Similar to 6" and 12" extensions.