This is the Promag Sig P365 50-round drum magazine. 

Note: this drum magazine will fit SIG P365, P365XL, and P365X pistols only. It is not compatible with P365X-MACRO, AXG Legion, FLUX, or FUSE models.

If you’re looking to maximize your range time with less reloads, this 50-round drum magazine is for you! Between the DuPont Zytel based polymer drum and steel tower, it doesn’t get much more durable than this offering from ProMag.

Best of all, this drum mag is made right here in the USA and is backed by ProMag’s lifetime guarantee against manufacturer’s defects.

Pick up one of these 50-round drum magazines and get ready to hit the range!