"The CSW uses a standard AR15 lower receiver and is completely modular. Franklin Armory will offer this product in three variations. Pictured is the CSW-V1 variant. The retail price is around $2199.99. We have a lower cost version featuring a V4 upper for $1649.99, and we will also make it
available as a kit for $674.99. "
Now I know what to do with one of those extra lowers I have!