We are offering this bunker portion of our coal yard kit as a separate accessory for those of you who wish to create a retail coal, gravel, sand or limestone yard and already have a building but need the bins. This kit comes with four side walls and three end walls, for a total of 7 parts. The highly detailed pieces are made of polyurethane resin that is dyed gray. This kit is easy to assemble and can be made to have curved or straight walls. The photos show a semi-circular version of bunker set-up. Coal piles and conveyor are NOT INCLUDED.