I have previously purchased the ones seen on the TV ads and they were great, so I bought these thinking they were the same but cheaper...boy was I wrong.  First these do not have the Claw clasps on one end to attach to your existing necklace/bracelet latch.  Nooooo....these have closed rings on each end, so how am I supposed to attach them?  Take them to a jeweler and pay to have the rings opened and then attached?  They also say they "lock", but I don't see any screw grooves, these just have a smaller unit that inserts into a slightly larger side..  To me these do not "lock".  If you want good ones, pay the extra and get the ones as seen on TV.  They have the claw ends, and actually "screw" into each other.  Needless to say these are useles.