Im selling an upgraded M249. It works perfectly on an 11.1v lipo and shoots crazy fast. Ive installed: A retractable buffer tube stock a high torque Godzilla 5k motor M120 spring (I'll include the original spring) I chrono'd it around 310 fps with a .25 but that can be changed easy because this gun has a quick change spring system. The gun only has a couple minor paint scratches but that can be easily touched up. ** I recommend a high output LiPo or else the rof will be extremely low. **