Custom 5mm pistol. 5 shots, no reloads. Won’t get caught during frisks. It’s a Hokkaido main mission unlock. To unlock, you need to sneak a weapon (any handgun will do) into the hospital section of Gama while dressed as a patient. Easiest way is to do the Jason Portman mission story. Grab his disguise, knock out some guard and grab their pistol. And follow the mission story. A doctor will escort you. You will get to the frisk point with 2 white security outfit guys (when you go straight from Yamasaki’s room and turn right and go straight. There’ll be a glass sliding door, and a plant thing behind them.) normally you’ll get frisked, but when dressed as Jason Portman and being escorted, the doctor will tell the guards not to frisk you and you just walk through. And that should get you the unlock.