Choice of non bridged or bridged exhaust port.
Kit consists of:
Manifold ( left or right ) for 30mm Carb
Excerpt from the Lambretta Images Archive GT200 blog..
"The exhaust timing on the standard kits running with a standard crank (58/107) are:
bridged 178 degrees
Unbridged 181 degrees
On the current batch of the barrels (May 2015) the port heights have been .........."