Bicycle Tag of bike

btw, that antenna thing on the lamppost is part of a sound artwork by Graeme Miller called Linked made shortly after the road finally opened in 1999. Positioned along the route are 20 radio transmitters each continuously broadcasting different voices of residents affected by the construction of the road, some in favour of it, some very much opposed. You can hire special headsets from Leyton Library to tune in.

I was wondering what that was. Thanks.