Brian, it's a suction pad (cupping glass its a medical device that we use to make suction, its like a inverted cup with a small piston to extract air). I used it to remove the cap of my old mustang, I've not tried in my BDR but I think I would work in a similar way.
Lugo is a small european town (aprox 100.000) in the north of Spain. The city is rounded by a 1rst century wall (yes! almost 2000 years old) that was declarated World Heritage two years ago.
www.muralladelugo.info
Cheers
Alfonso