We have been debating what these birds could be –- swifts, perhaps? We had a customer in our shop who painted hers in black and left some silver bits which produced a very realistic looking magpie! Regardless they are lovely and as they are reversible, they feel solid and rounded. Available in antique silver and antique bronze. They measure 25mm long, 13mm tall, and 5mm wide. The ring opening is about 1.5mm. Made of zinc alloy that is lead and nickel free.