Hi Jrmc. Welcome to the ECF. Do you mean the sleeve on the ends as if when it was new? Kind of clear opaque, made from silicone? If thats what you mean then Yes , Most folks refer to them as carto condoms. They should be included with all new cartos. I keep a few around that come on the Boge cartos that I keep around the house. If you ar looking for just the covers, then I dont recall seeing them for sale as is, without a carto. But if you scour the web long enough you may eventually find them. Otherwise just search up the 510 threaded cartos that would work on your Blu, most 5packs are around $7, for the brand name ones like Boge, Smoketech etc. If you do get a pack of cartos be sure they are not lower than 2.5Ω for them to work correctly on your Blu. Good Luck, Happy
vaping.