The team at Petrawell combined a few unique characteristics to the already versatile Picatinny Rail namely the M-LOK system and the Quick Detach sling mount point. M-LOK, standing for Modular Lock, is a free licensed firearm rail interface system developed and patented by Magpul Industries. Quick Detach sling mounts (QD), also called Flush Cup sling mounts, is a type of mounting point used for attaching slings. “QD sling swivel” usually refer to the part attached to the sling, while “flush cup” refers to the corresponding socket on the firearm or in our product milled into the Picatinny Rail. These additions add more flexibility and options to mount and or attach other additional firearm accessories.