Neodymium magnets.  Be careful who you ship with when buying them from outside Canada.  If customs knows you are importing neodymium magnets they slap you with an extra fee.  When I ordered 40 dollars worth of magnets, the fee was 30$.  Turned a good deal to a shit deal.  Unpleasant surprise getting my package and having to go find some cash in my housecoat to pay the driver. UPS is bad.