From their announcement:
There’s 25% off the price of sewers. Order your 25/28mm resin sewer models now for collection at Warfare (postage will be refunded) or for delivery before Christmas.
There are two types of sewer for historical or role playing gaming: traditional Victorian brick for WWII, steampunk, gothic etc..or the modern concrete type for near future, post-apocalypse etc... You can add a whole subterranean level below your buildings. Both types are modular and fit with the modular road sections, cellars and even buildings to give a 3rd dimension to urban battlefields and FIBUA. The road sections fit over the top of the sewers, which can be used for hidden movement and ambushes. Check out the new ‘Gallery’ for demonstration photos of this arrangement.