Seekins Precision Havak PH3 6.5 PRC 20" Black Fluted Threaded Barrel, Black Picatinny Rail Steel Receiver, Adj Cheek Riser Mountain Shadow Synthetic Stock The Havak PH3 rifle features an integrated 20 MOA Picatinny rail; a full-length M-LOK rail; adjustable cheek piece; a Seekins quick-change barrel system with a 3-lug bolt design and 60-degree throw; toolless bolt disassembly for caliber changes and cleaning.