Must be in every car mechanic's tool box. Incredibly comfortable. Same as the standard size 21-hole MINI V-DrillGuide from Big Gator Tools. I'm thinking of buying this and a MINI as a gift for my boyfriend. You can insert a transfer punch into one of these pilot holes, which fits exactly like the drill. You can then apply a bubble level (or your smartphone's goniometer) to the transfer stamp before tapping to ensure you drill and/or cut the hole exactly where you want. I don't see any way to get less than 5 stars. Make sure you oil it or put WD-40 on it before putting it in the box. It is bare metal and can rust easily.