Schwalbe 16" / 18" Brompton presta inner tube - SV4 Linkglide The controller is a part

The controller is a part that you cannot see on the bike

Seatpost: Brompton Extended Chromoly steel tube - gloss black

Name GP1 Use Mountain Bike

The mount is screwed to the hub and holds your Smartphone with a spring clamp absolutely secure - even off-road

Schwalbe 16" / 18" Brompton presta inner tube - SV4 Linkglide The controller is a partThis is a thinner than normal Brompton tube with a presta valve (aka french value, high pressure valve or 'that skinny valve'). This is not for standard brompton setups, this is the one you need when you are using racing tyres on a Brompton such as the Schwalbe Kojak or Schwalbe One (tanwall) tyres.