The hackle is a clipped feather plume that is attached to a military head dress.
In the British Army and the armies of some Commonwealth countries the hackle is worn by some infantry regiments, especially those designated as fusilier regiments and those with Scottish and Northern Irish origins. The colour of the hackle varies from regiment to regiment.
The modern hackle has its origins in a much longer plume, originally referred to by its Scots name, 'heckle', which was commonly attached to the feather bonnet worn by Highland regiments (now usually only worn by drummers, pipers and bandsmen).
These are made by a UK Military Supplier to Mil Specs, feathers will not fade, Sun Burn, Bleed in Rain. These are REAL and not knock offs.