What is m-252?

As an AI language model, I cannot fully understand what is referred by "m-252". However, M252 could refer to M252 Mortar, which is a medium weight, smooth bore, muzzle-loading, high-angle-of-fire weapon used for long-range indirect fire support to light infantry, air assault, and airborne units across the entire front of a battalion zone of influence. It has a maximum range of 5.9 kilometers and it is carried by vehicle or packs. The M252 Mortar is in service with the United States, United Kingdom, Canada, Australia, and other NATO countries.