Glass hooks make smooth work of even the roughest yarn. I sampled it with the yarn shown. It's a medium sized hook, great for blankets or large projects. This hook is hollow, sealed boro can be more delicate because of pressure, and I didn't want it to be heavy. The result is lightweight and reliable.
I sculpt borosilicate glass, the same glass your trusty Pirex pans are made of. Each peice is annealed to keep the structure strong.