QISF 7Pcs 300mm Extra Long Twist Drill Bits Set (4-12mm）+ 9Pcs Woodworking Drill Bit Depth Stop Collars Ring Locator (3-16mm)，for Wood Hole Cutter Drilling DIY Plastic

if you need a super long thin drill bit then this is for you.be careful though as the thinnest one is pretty fragile.

Absolute rubbish. Not lasted even one hole. As you can see in the picture, I tried both 4 and 6mm. Both just broke as if they're made of some very soft metal. I wonder who are those people who give 5 stars. Surely they never tried to use this.

perfect

Use the thinner drill bits carefully not to snap them. They are thin and will definitely break as I found out. Having said that they do work just fine, but I wouldn’t recommend using such a long thin drill bit in hard wood.

The lengths are very much an advantage for me.

Purchased these to do fome work to my log cabin office.I needed to drill through around 15cm of wood to run cables, etc.First impression upon opening them was that they are very cheap, the plastic wallet the come in was already starting to fall apart.Upon trying to use them I found they were not straight and any pressure I put upon them caused them to bend further..That said, they did the job well enough.. although I was only drilling through pine, anything harder and I don't think they would have managed..The drill bits are soft so that did allow me to straighten them slightly, but i don't really see that as a positive..Overall they did the job but I wouldn't buy them again...

So initially they actually look pretty good and don't feel too bad either but that's where the story ends. I used the 4mm bit and I got half way through the job and it bent and twisted like a liquorice stick before snapping. Yep it snapped in the hole and the only way to remove it was with locking pliers. I know the thinner bits will need to work under immense pressure and stress but surely it should do better than 1/2 job? Incidentally I was drilling into a dry log without knots..

Nothing to dislike.