Complex sentence: The MG 81Z was found in many unique installations in Luftwaffe combat aircraft, such as a pair of MG 81Z (for a total of four guns) installed in the hollow tail cone of the Dornier Do 217.
Split into simpler sentences: The MG 81Z was found in many unique installations in the Luftwaffe's combat aircraft. Some of the more known applications, are a pair of MG 81Z's installed in the hollow tail cone of the Dornier Do 217.