Just make sure the Hot Fix you buy has the glue thingy..
Hot Fix: HOTFIX flat backs (HF) are loose crystal components with a flat reverse side that has been pre-coated with a heat sensitive glue.
to buy my Swarovski's from: www.hotfixqueen.com
The ones at HL, make sure it has the pre-coated glue as I've only seen the regular flatbacks (even tho it says Swarovski's). Also, those kind (that say's Swarovski's..not just the craft crystals/rhinestones), one can use E6000. I mean, I've used E6000.