If you still prefer old-style RIS for your M4 handguard than M-Lok or Keymod? You can still pick one of the Colt M4A1 RIS Metal AEGs With Crane Stock that Airsoft Atlanta got available... "The full metal Colt M4A1 RIS (quad rail system) Carbine Metal AEG with metal barrel is a great airsoft gun with the features players most want. Full metal receiver and metal parts where it should be. Upgraded internal V2 gearbox with better than OEM parts. 14mm CCW metal threaded barrel. Standard M4 quad metal rail system handguard.

Solid upgraded gearbox and internal parts for this licensed Colt M4 airsoft gun. Out of box FPS is 380 with .20 gram BBs. Uses all standard airsoft M4 parts, magazines, QD metal top handle, etc. Fully licensed Colt model M4.

Includes NiMH battery, Charger, and one 300rnd metal hicap magazine. 9.6v 1600 or 7.4v nun-chuck batteries recommended (sold separately) along with a smart charger. The box includes a starter battery and charger, but we recommend getting better ones at some point. Battery goes in the front handguard area."