Not many if you wish to sell it on eBay. EBay are following the legal requirements of uk govt over bladed items, although if honest I do feel a hedge trimmer is a bit extreme.
the problem is you could sell that item to a minor (I am not saying you would) but eBay have a legal obligation to comply to the law and are thus taking a blanket rule to matters. That items if this nature need to be sent on an age verification service.