Eduardo, this UPC code Rifle has Forged Aluminum Lower Receiver and a Forged Aluminum Upper Receiver. ((Specifications and Features)): - American Tactical Imports MILSPORT Rifle - TIG15MS556P3P - AR-15 Semi Automatic Rifle - 5.56 NATO accepts .223 Remington - 30 Rounds - 16" M4 Profile Barrel with a 1:8" Twist - Threaded Muzzle 5/8x32 TPI with Flash Hider - Forged Aluminum Lower Receiver - Forged Aluminum Upper Receiver - Flat Top Optics Ready Upper - Keymod Handguard - Collapsible Stock - Black Finish - Overall Length 32.25" to 35.5" - Weight 6.5 lbs. It does have an installed NANO COMPOSITE PARTS shown here : americantactical.us/5881/detail.html

Hi,
The lower receiver is a metal reinforced polymer. There is no finish as it is a polymer part. I hope this helps.