From the release:
Prepare your assault with Sally 4th Siege Engineering Equipment.
This week sees the release of an additional 3 siege engineering products to assist a besieging forces preparations for a determined assault on a castle, fortress or city walls.
Covered Way 28C_031 £5.50
Construction of a covered way allows besieging troops to approach the base of an enemy castle or fortress with complete protection from missile fire from the walls. These would be constructed by siege engineers in a protracted siege to either give miners or sappers protected access to reduce the masonry at the corner of towers, or it could be used to give assaulting troops cover to approach a breech. The Sally 4th model is 54mm wide and 90 mm long. The roof is removable during use to allow miniatures to be placed inside. Multiple sections of covered way can be deployed to stretch from your siege lines to the castle wall.
Wooden Palisade Fencing 28C_032 £3.50 for 2 sections
The besieger needs to protect their forces prior to assaulting a fortress as siege warfare is a lengthy activity. Wooden palisades need to be constructed to protect from missile fire from the castle walls. Kit contains 2 sections of fencing, each 100mm long.
Wooden Roadway 28C_033 £3.50 for 2 sections
Probably the least glamorous wargames model launched ever, but try advancing wooden wheeled penthouses and siege towers over rough ground without laying a prepared roadway first. Kit contains 2 sections of wooden roadway, each 100mm wide x 90mm long.