m tac patch zu 23 4 pvc 8624M Tac has introduced a new PATCH ZU 23 4 (PVC) as part of its ongoing series of military themed patches. This patch is an excellent addition to any collection for military personnel and enthusiasts of military style. The patch depicts the Soviet self propelled artillery system ZU 23 4 "Shilka," which was introduced in the 1960s for the purpose of providing anti aircraft coverage for ground troops. Despite its age and limited numbers still in service