Polos are a brand of sweets whose defining feature is the hole in the middle. The peppermint flavoured polo was first manufactured in the United Kingdom in 1948 by employee John Bargewell at the Rowntree’s Factory, York, a range of flavours followed. The name ‘Polo’ is reportedly from the word ‘Polar’ and is to symbolize the cool and fresh feeling one gets from sucking a Polo.

Info gleaned from Wikipedia