=== M21 EBR Custom ===
''The M21 EBR Custom kit replaces the M21's old wood frame and stock with the EBR frame, made out of aluminium, steel, and polymer. It features a retractable stock, a pistol grip, and long accessory rails. In addition, a threaded barrel is installed, for compatibility with standard muzzle devices. No top rail is added; the original 9x scope is retained instead. The bayonet lug is preserved, so that you may still attach a bayonet if you so desire.''
Cost: [[File:Parallar symbol.png|10px]]'''600'''
* Stock type: Becomes '''Retractable (RS)'''.
* Muzzle: Becomes '''Standard devices'''.
* Optics: Becomes '''NATO mount'''.
* Underbarrel mount: Becomes '''Long interface'''.
* Lights: Becomes '''2x Long interface'''.
* Stock type: Becomes '''Retractable (RS)'''.
* Muzzle: Becomes '''Standard devices'''.
* Optics: Becomes '''NATO mount'''.
* Underbarrel mount: Becomes '''Long interface'''.
* Lights: Becomes '''2x Long interface'''.
* Stock type: Becomes '''Retractable (RS)'''.
* Muzzle: Becomes '''Standard devices'''.
* Optics: Becomes '''NATO mount'''.
* Underbarrel mount: Becomes '''Long interface'''.
* Lights: Becomes '''2x Long interface'''.
* Stock type: Becomes '''Retractable (RS)'''.
* Muzzle: Becomes '''Standard devices'''.
* Optics: Becomes '''NATO mount'''.
* Underbarrel mount: Becomes '''Long interface'''.
* Lights: Becomes '''2x Long interface'''.