Hi! I will try to help you, but I could be very very wrong!
I'm almost completely sure that it's a Den. Funnily enough, it looks alot like the Den I've been trying to get info on before buying it, which is Den. aggregatum (also known as Den. lindleyi) It could be Den majus, which is similar. If it's the mini version, then it could be Den. jenkinsii. Do any of those names see familiar??
Have a look at this thread, there are pictures of Den.aggregatum. It looks alot like yours!
Den. aggregatum
I really hope that this will help!