Brief info of Tri Rail AR Barrel Mount:
1) Three Rails, 6 Slots Each Rail
2) Fits Regular .75" Barrel
3) Aluminium Alloy

The detail info of MTS3020  Tri Rail AR Barrel Mount:

1)Three Universal Rails, 6 Slots Each Rail
2)Easy To Install 
3)Hard-coat Anodized Finish
4)Premium Aircraft Grade 6061 Aluminum
5)Complete with Barrel Adaptors and Stabilizing Design to Guarantee Rock Solid Attachment 
6)Fits Regular .75" Barrel