Most teams are comprised of seven members: commander, team leader, scout, backup, marksman, spotter, and gasman. Only the most qualified applicants should be selected for such specialized teams. Criteria for selection used by departments usually require marksmanship, a stable and well-balanced personality, good physical condition, and the ability and discipline to function as a member of a team. Most teams wear standard green fatigues and protective vests. A glass-bedded, scoped, bolt-action rifle with a heavy free-floating barrel is the most popular weapon used by teams. The 40XB, the Remington 700BDL, and the Ruger 77V are among popular makes. Members not required to carry a specific weapon because of their position often favor semior fully automatic weapons. Shotguns are used in some situations. In addition, every team member should wear a semi-automatic pistol or revolver. Training should cover the use of weapons and chemical agents, hostage negotiation and rescue, entry methods, scouting procedures, and repelling techniques. Well-trained SWAT-type teams, while expensive, have shown themselves to be effective in dealing with snipers, barricaded criminals, hostagetakers, and other violent individuals.