The First Factory Rail Stock Base is designed to be compatible with the First Factory (Laylax) Picatinny rear stock base series, as well as airsoft models equipped with a Picatinny rail on the stock base. Notable examples include the SIG Sauer Proforce MCX and MPX electric airsoft guns manufactured by VFC (licensed by SIG AIR). This versatile accessory allows for customization by combining it with various airsoft M4 / AR-15-compatible retractable stocks, enabling you to achieve the desired aesthetic.

It's important to note that the stock and buffer tube are not included with the First Factory Rail Stock Base. If you require a buffer tube, it is compatible with the LayLax "Rail Stock Pipe Adapter Light." However, depending on the specific buffer tube utilized, there may be slight gaps that require fitting or modifications during installation.

The length of the fixing screw (M5 0.8) may vary depending on the type of stock pipe employed. It is crucial to ensure that the fixing screw is not included and must be obtained separately. Please refer to the provided diagram for the correct dimensions, particularly ensuring that the screw does not protrude more than 5mm from the end face of the stock buffer tube. If the screw is too long, it will need to be trimmed accordingly to achieve the ideal fit and functionality.

First Factory Rail Stock Base
First Factory Rail Stock Base is compatible with First Factory (Laylax) Picatinny rear stock base series and airsoft models with a Picatinny rail on the stock base.
Compatible with SIG Sauer Proforce MCX and MPX electric airsoft guns by VFC (licensed by SIG AIR).
Allows customization by combining with various airsoft M4 / AR-15-compatible retractable stocks.
Stock and buffer tube are not included.
Compatible with LayLax "Rail Stock Pipe Adapter Light" for buffer tube.
May require fitting or modifications for proper installation depending on the buffer tube used.
Fixing screw (M5 0.8) length may vary based on stock pipe type.
Fixing screw is not included and must be obtained separately.
Refer to provided diagram for correct dimensions.
Ensure the screw does not protrude more than 5mm from the end face of the stock buffer tube.
Trim the screw if necessary for proper fit and functionality.