You can get them on eBay but not from UK (nightmare) cheapest I can find works out around £16 for 12 including delivery http://www.ebay.co.uk/itm/12-BLACK-connector-wire-snap-grid-storage-cube-unit-NEW-/190576452754Thank you really need to do the one on the floor with the two tier better, need more Seville connectors but I don't know where you get them from :/
You're welcome! I didn't realise they had different sizes oops! Hope they are the right ones!Thanks @HansPiggies I'm going to measure mine and see if they are the same I'll order if they are! Thanks again your a star!