Internal receiver cam rail for the Scar(tm) 17s and CypherX receivers. New. 
- Replaces FN(tm) part F182120010
- Machined from S7 Tool Steel for a lifetime of reliability
- Slick black oxide finish
- Has the same weight-reducing features machined in as the original factory rails
 
                     
                     
                     
             
             
             
            