Gas System Store / Gas System BRT Gas Block - Gas Tube AR-15 5.56 NATO AR15, M16, M4 Made in USA BRT MicroPin Gas Block - .750" BRT MicroPin Gas Block - .750" $59.95 BRT Gas Block Pin Kit - Coil Pin BRT Gas Block Pin Kit - Coil Pin $5.95 BRT Gas Block Screws ( 6 pcs ) BRT Gas Block Screws ( 6 pcs ) $4.95 BRT Gas Block Pins ( 3 pcs ) BRT Gas Block Pins ( 3 pcs ) $4.95 BRT MarkBlue Gas Tube - Pistol BRT MarkBlue Gas Tube - Pistol $14.95 BRT MarkBlue Gas Tube - BRT EXP BRT MarkBlue Gas Tube - BRT EXP $19.95 BRT MarkBlue Gas Tube - Carbine BRT MarkBlue Gas Tube - Carbine $15.95 BRT MarkBlue Gas Tube - BRT EXC BRT MarkBlue Gas Tube - BRT EXC $19.95 BRT MarkBlue Gas Tube - Midlength BRT MarkBlue Gas Tube - Midlength $17.95 BRT MarkBlue Gas Tube - BRT EXT BRT MarkBlue Gas Tube - BRT EXT $19.95 BRT MarkBlue Gas Tube - Intermediate BRT MarkBlue Gas Tube - Intermediate $18.95 BRT MarkBlue Gas Tube - Rifle BRT MarkBlue Gas Tube - Rifle $19.95 BRT MarkBlue Gas Tube - Rifle +1" BRT MarkBlue Gas Tube - Rifle +1" $21.95 BRT Gas Tube Pins ( 3 pcs ) BRT Gas Tube Pins ( 3 pcs ) $4.95 Pin BRT Gas Block Pin BRT Gas Block $50.00 Pin BRT Gas Block - Existing Upper Pin BRT Gas Block - Existing Upper $100.00