This is a Samson Manufacturing Corp. Rail known as the Evolution, model 2_Rail_Kit.
Evolution accessory rails can be added or removed at any of 7 positions around the rail and any place along the length of the tube. Compatible with Evolution Series only and RTR Series. 2" Accessory rail kit includes two rails.
Features:
1913 Picatinny Mil-spec
Compatible with Evolution Series only and RTR Series
Includes 2-2 rails
