Specialized signalling mirrors are available and are often included in military survival kits.
2.
Some of the common reasons for the holes include thumb-opening ( as in the one linked by Recury ), creating an inclinometer, sighting hole ( using the side of the knife as a signalling mirror ), wire stripper, bolting on attachments ( silliness ), or even to include a small magnifying glass for firestarting ( true silliness in a knife ) . talk ) 00 : 52, 24 May 2009 ( UTC)
मोबाइल