M16A4 Rail System

[AMBUSH]

Who makes it and where can I get it?

[pettifogger]

Knight's Manufacturing Company (http://www.knightarmco.com/) M5 RAS.

You can buy it from many many retailers and dealers. For example:

http://www.calssportingarmory.com/
http://www.gandrtactical.com/
http://www.impactguns.com/
http://www.jtdistributing.com/
http://www.operationparts.com/
http://www.mstn.biz/

[AMBUSH]

Thank you sir.