Bought several 510 thread cartridges for a vape pen and had issues with one cartridge. It would give you 2 solid hits then it would start flashing like the battery was dying. Thought it was my battery but changing tips would always make it work. Called the store and was told they would exchange it but once at the store was told it wasn’t considered an exchange because in there opinion there was too much gone from the cartridge . Regardless of the defective product that doesn’t work no warranty was given. Considering this I would not recommend this storefront and will give my business to OCS which now delivers to your house. Save your money and go to the OCS