From back cover:
Battlefields is a set of four new "Geomorphic" maps designed to connect to the G.E.V. and Shockwave maps . . . making it possible to create maps over 2' by 3'! you also get rules and counters for:
Engineers. Build bridges and other structures . . . or blow them up.
Revetments. Prepare defensive positions to increase the survivability of your force.
Militia. The ultimate cannon fodder.
Also included are nine new scenarios and varients to let you fight the Last War across new battlefields.