Коробка рыболовная Flambeau "Greek Magnetic Fly Box", Large

Or water and gas pipes can be used. Significant research is also going on in the field of electro-optical communications. Dead-letter boxes are the favourite GRU means of contact. They have the most universal application and in addition to communications they may be used for the storage of everything that has to do with a spy's work - documents, money, radio sets, special photographic equipment, for example. Thousands of types of dead-letter boxes are known, from cracks in gravestones and brickwork to specially devised magnetic 'letter boxes' in the form of metal nuts. Applied to the structure of a bridge among thousands of similar nuts and rivets this device is easily hidden and just as easy to undo. The GRU also makes wide use of boxes constructed in the form of a plastic hollow wedge with a lid. These can very easily be pushed into the ground in any public park. Underwater dead-letter boxes are also widely used. Their selection is always a complicated and responsible business. The primary criterion is that as far as possible they must not be prone to accidental discovery ...»