Early model No. 106 Mk II, without safety shutter, 1917
Later No. 106 E Mk IV with safety shutter, showing before use, before firing, during flight and on impact, and action of tape and shutter
Unassembled 18-pounder shell, 106 Mk II fuze and safety cap
The number 106 fuze was the first British instantaneous percussion artillery fuze, first tested in action in late 1916 and deployed in volume in early 1917.