These are sturdy solid plastic units purchased from a large National retailer to create a base for a new garden shed, They were unpacked but never needed as our existing concrete slabs worked. The units are interlocking and each square is 49 cm x 49 cm x 4cm). THERE ARE 11 ALTOGETHER. Each square has an internal design allowing pebbles or stones to be loaded within the perimeter giving added strength, drainage and security. They are presently on sale at £6 each in the retail chain. I would prefer to sell all 11 units as a lot @ £3.00 each, making £33 in total, buyer to collect from Carnoustie, Angus. However, in the absence of a full sale offer I would accept £3.50 for individual units at a later date.