the f-27-b F.L.S.M. (front line scout mech) is basicly the F-27-a stripped down to be lighter taller and faster. taking the lage engine and mounting it under the carrage instead of in the back and mounting its light Railgun on top of the carrage aswell the legs are thinner and longer to provide more speed and mobility.
About this creation
here we can see the much thinner legs and the changed position of the gun and engine
the main hatch has also been moved to cover the back portion of the walker here it is closed