Oudtinz 30 Pack 1mm Diamond Drill Bit Jewelry Beach Sea Glass Shells Gemstones Lapidary 30pcs.

Very flimsy you have to be very careful when using these as they break very easily

Last really well

Each drill bit has a Dimond coated end.Excellent.

All the drill bits were lose in the box and were actually one short

Good value sturdy good for money