Page "M4 carbine" Paragraph 29

Variants of the carbine built by different manufacturers are also in service with many other foreign special forces units, such as the Australian Special Air Service Regiment ( SASR ).

While the SASR uses weapons of essentially the same pattern built by Colt for export ( Colt uses different models to separate weapons for the U. S. military and those for commercial / export purposes ), the British SAS uses a variant on the basic theme, the Colt Canada ( formerly Diemaco ) C8SFW.