Any adapter with an empower tip will do. Most have a small adapter that pushes over the empower tip to convert that to a standard cigarette lighter type tip for when that is needed, but unfortunately not the other way round. However, perhaps such a converter does exist ?? If so it should not cost more than a few pence.

You should be able to buy an adapter with empower tip on Ebay and can sometimes get good prices. Otherwise, just get one at the aiport ad suggested above. Cheaper than the BA adapter.

Also, the BA adapter converts from empower to US 2 pin (IIRC), so you also need your mains power block with you and, if relevant, a US 2 pin adapter. It does mean that the BA adapter with work with any laptop, whereas the other adapters come with a range of power tips to connect straight to your laptop. You then have to make sure they have the right one for you model !!