The Vauban style of Fortification was very complex and had many elements in addition to the walls and bastions. This kit allows you to add Demi-lunes (also called Ravelins), which were triangular shaped walls built beyond the main walls of the fort. This kit includes four Demi-Lunes. One of them had an opening in it to allow a road to pass through while the other three are solid. The kits come in 10/12mm scale, 15mm scale, 20mm scale, 25/28mm scale and are also available in either brick or stone finishes.