The Accuracy Systems Ruger Mini-14 and Mini-30 Gas Block is manufactured from 7075 Alloy, which is pound for pound Stronger than steel but half the weight with faster heat dissipation. FeaturesThicker stronger top than the factory top.Fits all after market products.Same bolt pattern.Will fit Sampson Hannibal Rail, Amega Ranges, ULTI-MAK Scout Mount & Ranch Products Scout Mount.Swivel stud is removable and is more functional than the factory fixed loop.Comes with Top, bottom, (4) 8/32 mounting screws, swivel stud and wrench.Comes in .625" size for Post-580 serial number prefixes 580 Tapered barrels thru 586 Mini 14, Target, 6.8 and All Mini 30s.