Police Long Service and Good Conduct Medal

The Police Long Service and Good Conduct Medal is a decoration for police officers of the United Kingdom. First instituted in 1951, the medal is presented for twenty aggregate years of service in the police services of the United Kingdom.
Criteria.
The Police Long Service and Good Conduct Medal was instituted under Royal Warrant by King George VI in June 1951 and is awarded as a mark of the Sovereign's appreciation of long and meritorious service rendered by members of the Police Forces of the United Kingdom. For an officer to become eligible for this award the Chief Constable must make a recommendation to the Home Secretary, and in doing so, is required to certify the following:
Commonwealth.
In 1956 eligibility was extended to police officers serving in Australia, Papua New Guinea and Nauru. In 1976 Australia replaced the award with the National Medal and, in 2010, with the National Police Service Medal.
Length of service.
The initial award criteria was 22 years' service as a full-time regular police officer within any Constabulary. Later, Long Service and Good Conduct Medals were introduced for the Fire Brigade and Ambulance Service, both awarded for 20 years’ service. A national campaign to award the police medal after 20 years, and so bring it in line with the other emergency services, was started by Warwickshire Police Officer Kenneth Fowler, supported by Chief Officers, the Police Federations and Members of Parliament. On 19 January 2010, Queen Elizabeth II amended the medal's royal warrant to make the qualifying period of service 20 years.
Appearance.
The medal is circular, in diameter and initially issued in cupro-nickel, with modern strikings being rhodium plated. It has the following design: 
Welsh language ranks on LSGC’s, was introduced in 2006, as an option for officers serving in Welsh forces. 
There being 4 Welsh Forces in total - 
North Wales Police - Heddlu Gogledd Cymru
South Wales Police - Heddlu De Cymru
Dyfed Powys Police -  Heddlu Dyfed Powys
Gwent Police - Heddlu Gwent
The ranks being - 
Constable - Cwnstabl
Sergeant - Rhingyll
Inspector - Arolygydd
Chief Inspector - Prif Arolygydd
Superintendent - Uwcharolygydd
Chief Superintendent - Prif Uwcharolygydd
Chief Constable - Prif Cwnstabl
Obverse variations.
The medal has been awarded with one of three obverse designs: