Warhammer Fantasy Roleplay 4th Ed Gamemaster Screen - Rules of Play says:
Striking and sturdy, like Altdorf’s reliable redoubts, the Warhammer Fantasy Roleplay Gamemaster’s Screen provides a succinct summary of WFRP’s important rules alongside an essential range of Gamemaster’s tools. With breathtaking artwork of the Old World’s festering cities on one side; important tables, references and rules on the other – the GM Screen is an ideal component to keep all your nefarious plans hidden from your players’ prying eyes.
Accompanying the screen is the Gamemaster’s Guide, a 32-page booklet packed with practical tips, clever tricks and optional rules, and indispensable articles for GMs both new and old. The Gamemaster’s Guide and the Gamemaster’s Screen will expand your campaigns in new, innovative and exciting directions.