The Game Master's Kit (Dark Heresy, First Edition)

From the back of the book:

This lavish Game Master's Kit helps to keep all Inquisitorial secrets safe! Behind the sturdy screen the GM can hide dice rolls and keep players from reading his notes. Printed on the GM's side are numermous handy quick reference charts that make running the game that much easier. Added to this is a 32 page booklet with a full adventure, xenos generator and new rules for poisons and toxins!