An extension for set number sixteen (16A) includes 267 stone blocks in the three standard colors; brick red, natural sand, and slate blue. The Designs for Architectural Models booklet includes ten building plans for large and complex buildings including a parish church and city hall. Packaged in the traditional wooden box for storage with a packing diagram and construction templates. This expansion allows you to build the largest and most complex models. This set plus the combination for set #16 becomes the equivalent of set #18 and allows you to build all of set #18 models.