The Aero Precision M5 Complete Lower Receiver with Magpul SL-S Carbine Stock is the perfect upgrade for your AR build. This complete lower features an M5 (.308) Lower and is upgraded to include an Magpul SL-S Carbine Stock. The storage-capable version of the flagship Magpul MOE SL™ carbine stock, the MOE SL-S (Storage) Stock is a replacement buttstock for .308 carbines.