Just thought that i would add that only Baltic Amber is affective...
The cheaper ones may be amber, but if they do not have the succinic acid it will not work...

Natural pain relief provided by Amber works by placing the necklace on your body, this allows your skin to warm the amber beads, releasing healing oils which are then absorbed into the blood stream. Only Baltic amber contains succinic acid, please beware of other sellers stating they sell "Baltic amber" yet the amber may be mined in China, Africa, Australia, India or Tibet this is Copal and does not contact the active ingredient - Succinic Acid.
TBH i would rather pay more and know that i am getting the real deal, than spend less and not have it work...

ETA - the NZ ones look like they are the proper ones, as they state where they come from, i think i will get one from them as they are better value with the exchange rate...
Thanks Lisa for the link