The TZ-45 is a late-war (some might say last ditch) Italian submachine gun made in small numbers and notable primarily for being the first SMG to use a grip safety on the magazine well. The grip safety on the TZ-45 is actually quite significant, as it locks the bolt in place when either cocked or forward. This does accomplish the important safety feature of preventing the bolt from bouncing open on impact and firing, but it also means that the bolt cannot be manually cycled without engaging the grip safety. Not surprisingly, most later submachine gun designers using grip safeties would opt to have them not block the bolt being cocked.
Only about 6,000 of these guns were made in Cremona before the end of the war, and they were used mostly in anti-partisan fighting in northern Italy. They were chambered in 9x19mm and used standard Beretta 38 magazines, so they presented minimal logistical challenges to units already equipped with other submachine guns. After the was, the design was adopted with a few changes by the Burmese military as the BA-52.