Try this: http://www.capitalgardens.co.uk/acat...post_Bins.html

Looks similar to yours, costs 46 squid for 300l model. I have a similar bin
that works well. You can turn the compost a bit by just sticking a fork
through the top and twirling away while it's only part full, but once the
level starts to build up, to be honest it is easier to just lift the whole
thing off the pile and dig it out that way (there's no base to it,
remember). Just make sure you leave yourself enough space to do so when
siting the bin. (Hint: behind the shed may keep the bin out of sight, but
doesn't leave much room for digging...)

Cheers,

Martin