 The WK180-C does away with the stamped steel and polymer construction of the AR-18, AR-180, and AR-180B, instead, it uses 6061-T6 aluminium to form the upper and lower receivers.This rifle ships with an adaptor to mount AR-15 style stocks (and comes with a collapsible AR15 stock).As LOP is long with many AR15 stocks, some users have retrofit Cz Vz58 folding stocks to these rifles.