The MP5SFA2 (SF – single-fire) was developed in 1986 in response to the American FBI solicitation for a "9 mm Single-fire Carbine".
It is the same as the MP5A2 but is fitted with an ambidextrous semi-automatic only trigger group.
The MP5SFA3 is similar except it has a retractable metal stock like the MP5A3.
Versions delivered after December 1991 are assembled with select-fire bolt carriers allowing fully automatic operation when used with the appropriate trigger module.

The semi-automatic "MP5SF" models are widely used by British police forces including London's  Metropolitan Police Service Specialist Firearms Command, Diplomatic Protection Group, Authorised firearms officers, and the Police Service of Northern Ireland to name a few.

The two-position trigger unit was used in the single-fire HK94 carbine that was produced specifically for the civilian market with a 420 mm (16.5 in) barrel.
The MP5SFA2 (SF – single-fire) was developed in 1986 in response to the American FBI solicitation for a "9 mm Single-fire Carbine". It is the same as the MP5A2 but is fitted with an ambidextrous semi-automatic only trigger group. The MP5SFA3 is similar except it has a retractable metal stock like the MP5A3. Versions delivered after December 1991 are assembled with select-fire bolt carriers allowing fully automatic operation when used with the appropriate trigger module.
The semi-automatic "MP5SF" models are widely used by British police forces including London's  Metropolitan Police Service Specialist Firearms Command, Diplomatic Protection Group, Authorised firearms officers, and the Police Service of Northern Ireland to name a few.
The two-position trigger unit was used in the single-fire HK94 carbine that was produced specifically for the civilian market with a 420 mm (16.5 in) barrel.
Heckler & Koch MP5