The Battle Arms Development's Rigidrail 9.5" M-Lok Handguard is designed to balance between light weight and strength/rigidity. The overall length is 9.5" and the inner diameter is 1.315". M-LOK Slots at 3" 6" 9" and partial 12 o'clock positions" and additional single M-Lock slots at four" 45 degree positions" for forward mounting light" laser" etc. It is compatible with AR-15 upper receivers and most low profile gas blocks.