It is what it says it is, fits, etc etc.

the heater block is perfect! Very easy to clean

Just get this and you will be happy. It keeps the heat where it is supposed to be at the hotend. I strongly prefer this new design over the old one. The old one would occasionally snag on the model being printed causing problems. I have done dozens of prints with the new silicon sock and no snagging issues - and I don't expect any ever as the silicon is not so close to the tip of the nozzle.

Hotend comes up to temperature faster, and won't cool appreciably, even with the 2 cooling fans running at 100%. Bridges are a lot better. Easy installation. Fast shipping.

These docks fit nicely, but it is hard to get them to stay seated in place.

Item as described - great feature

Now I am using this on the heater block of a clone E3d v6, and I have to say it's a good fit. If any of you have the Zorvo clone bought off Amazon, this is the sock for you. I run massive cooling on my carriage. 2 40mm fan set up, each duct blowing on the left and right of the nozzle, now even with PID tuning, it is still capable of making the heater run overtime and drop a few degrees. No doubt if not PID tuned, you will most likely see a huge drop in temps. After installing this sock, I can gladly say that it does EXACTLY what it is meant to. Which is make the heater block a nice blue color. Actually to hold in the temp to keep the heater block at a constant temp via insulating. As well as to keep the hurricane force cooling system from stripping the heat off the heater. All in all, the more constant your temp control, the more consistent the extrusion, and less clogging. I'd say this is one of the BEAT $2.50 investments you can buy, even for a cheap $20 clone hot end. So go forth my friends, if you have an authentic v6 or a clone, gather up your candy money and grab 1 or 10 of these. It's a great investment that works :)

Title says it all. Two things have been very noticeable since putting this thing on: 1) Hotend temps with the part fan running have been more consistent and stable. 2) Not a single issue with PETG sticking to the nozzle, something that plagued me before. Needless to say I'll be picking up more of these just to make sure I'm never without.

as advertized, delivery is prompt, happy to do business

These are amazing. Not sure how I ever did without them. The heater block heats up much faster, keeps that heat in and from transferring to the print. You would be crazy not to try these.