Silicon Sock for the style V6 blocks. For glass bead style thermistor.
they do not fit snugly onto the hotend, to get them to stay attached I had to put wire around the sock as there is not enough of a lip on the socks to keep them attached.
If you have an E3D v6 nozzle, you NEED this.
It really helps when printing small high detail parts. It prevents too much radiant from hiting your part and affecting previous layers.
Adding a sock really helps with temperature stability.
Your nozzle will keep homogeneous throughout the hotend, no matter if your cooling fans start/stop.
It also keeps your nozzle cleaner by preventing small strings and failed prints from sticking to the hotend.
Mine is slightly damaged in the picture, that's because I hit it really hard on my printbed :|
They fit really easy, no tools or adhesives required. (just like a sock)