• True monolithic design
• Rifle length - stripped upper, does not include barrel
• Designed for 14.5-20" MRP barrel lengths
• Made for MRP quick change barrels
• Two T-30 locking bolts for barrel change
• Allows for screw hole accessory attachment at 3, 6, and 9 o'clock 
• Locating lugs at 3, 6, and 9 o'clock 
• Full picatinny top rail
• 4 QD sling attachment points built in

Lewis Machine and Tool holds the patent on Monolithic upper receivers. Other companies closely replicate their upper design,  but cannot copy it. This SLK receiver is made for barrels ranging in length from 14.5" to 20" barrels since it is rifle length. You can quickly and easily change calibers and barrel length because of the MRP quick change barrel system. All that you need to do so, is a torch wrench that allows for torch up to 60 ft/lbs. of energy and a T-30 bit. You can attach your choice of accessories by using the locating lugs and screw holes at 3, 6, and 9 o'clock. The monolithic design allows you to place optics and other components wherever you want on the top picatinny rail. This upper receiver offers up features that literally no other upper does. 

For more info, visit LMT