Systema Complete Mecha-Box for MP5 Series (A4, A5, SD5, SD6)- Complete Drop In Gear Box for Full Stock Rear Battery MP5 with M120 Upgrade Spring for 370 - 400 FPS- All internal parts completed upgraded with Systema Parts (gears, bearings, tappet late, cylinder, bearing spring guide rod, selector plate, low resistance wires)- Completely Reinforced Heavy Duty Alloy Gear Box- Includes Torque Up Gear Set with Teflon Cylinder About Us: We are The Nation's Largest Airsoft Retailer and fully legalized corporation in the state of California. We have The World's Largest Airsoft Inventory and a 50,000 sq. ft. warehouse where all our merchandise is in-stock and available to be shipped immediately! Check out our listings! Payment:We accept Paypal ONLY for our eCRATER listings.Immediate Payment Required.Shipment: We ship Orders will be shipped out via UPS Ground. All orders areGUARANTEEDto ship within24 hoursof cleared payment (except weekends and holidays).Shipping charges arequoted directlyfrom UPSliveplus a $3.75 fee for handling.Orders will recieve a tracking number. Shipping outside of the United States is unavailable. Return Policy:At AirSplat we value our loyal customers satisfaction. We allow returns for a refund if you are not satisfied with your purchase. To qualify for a refund, request for return instructions must be made within3 days of delivery of your original order. NO EXCEPTIONS!All items must be returned in new or unused condition and include the original packaging materials included with shipment. All returns are subject to a15% restocking fee. Returned items will be inspected and issued partial refund less the restocking fee if opened or used. Please contact us with your order number located on your invoice via the email address we provide in the order confirmation email.Warranty:All items, unless specifically stated, are sold with a30 day warrantycovering manufacturer defects. Shipping will be the responsibility of the customer, we will provide the parts and labor. Warranty does not cover misuse or abuse!If we receive an item that has been misused or abused,we will discard or return it. Warranty also does not cover items without blaze orange tips. Items which do not have a blaze orange tip will bediscarded immediately! Please contact us with your order number located on your invoice via the email address we provide in the order confirmation email.Warranty does not cover:Disassembly by unauthorized personnelUnreasonable use or mishandling, introduction of foreign matter to inner or outer components.Failure to provide proper care, lubricants, or maintenance.Lack of compliance with instructions from the owners manual.Removal or cover up of orange tipMerchandise soaked in water, rusted, corroded, painted, or altered.Usage of low quality or low grade BB's or reuse of BB's.Contact Us: If you have any general questions or concerns, please feel free to send us a message or email us via the email address we provide in the order confirmation email and your questions will be answered promptly.Powered by eCRATER . List your items fast and easy and manage your active items.