A Police Support Unit or PSU is a unit of police officers who have undergone specialist tactical training in Public Order and Riot Control. About Police Support Unit training in the United Kingdom is voluntary tactical training undertaken by selected candidates that provides students with the skills required to safely and effectively deal with a variety of public order situations outside the remit or capability of regular divisional officers. Comparable units in the United States are local SWAT teams, trained to deal with situations beyond normal police work. PSU-trained officers in the UK are commonly referred to as Level 2, Mutual Aid Support Trained, or PSU officers. Equipment The majority of UK Police Forces use Mercedes-Benz Sprinter vans, commonly referred to as 'Carriers', as standard transport for PSUs. A notable exception is the Police Service of Northern Ireland, whose Tactical Support Group officers famously use armoured Land Rovers. These vehicles are equipped with mesh window shields and/or high-impact-resistant polycarbonate windscreens and outfitted with storage compartments for officers' riot control equipment as well as Method of Entry and CBRN kit. Carrier drivers must undergo specialist driver training in 'riot conditions' before qualifying as a carrier driver. The Metropolitan Police's Territorial Support Group also maintains a fleet of armoured Ford F450 based Jankel Guardians for use in serious public order situations, like the 2011 England riots. These are identical to, and interchangeable with, the Guardians used by SCO18 Aviation Command and SCO19 Firearms Command. Standard kit for PSU officers consists of a transparent acrylic riot shield, a baton, a visored 'NATO' helmet, shin and elbow guards, along with fireproof coveralls when required. Taser is a recent addition to the PSU officer's armoury. This level of protection allows officers to deal with a variety of violent situations, including riots, football violence and suspects armed with a variety of weapons. Some PSU teams are also dual-trained as first-line responders for CBRN incidents and carry relevant detection kit as well as major incident equipment. Training PSU officers are trained to a higher standard of operational readiness than their divisional counterparts. Training exercises undertaken encompass a variety of public order scenarios; officers will undergo extensive riot training including being petrol bombed in large scale engagements, prison clearance tactics, football stadium scenarios, night club scenarios, aircraft, rail and various 'angry-man' scenarios, as well as additional specialist training including use of stun grenades and distraction devices. PSU units