Full Metal Slide, Metal Outer Barrel, Magazine, Inner Barrel, Spring Guide and Frame.(All the parts that should be metal, is. Able to handle high pressure gas.- Full Auto / Semi Auto select Fire.- Lots of spare parts and custom parts.( 99% compatible with Marui & KJW M9 series.)- Railed Frame for External attachments (Optics, Laser...ect)- Spare Magazines Available.- On Frame safety.- Slide locks when mag is empty simulating the real thing!- Realistic Hard Blowback Kick Action.