Do not you find that a bunch of keys in your pocket slizhkom became cumbersome? Solder them in pairs, and it will be much more compact and easier to use. The keys are connected to a pair of depending on the length and destination. Possible combinations can be the key to the apartment and from the mailbox; the key of the garden gate, and to give the key to the garage and from the castle at the gate.
Recommend to read
CAPACITORS-GEMINI
Often, in order to work in a range of electrical oscillations of sound frequencies it is necessary to select the same capacitors. This and various or balanced bridge circuits, and is...
A BOAT FOR EVERY TASTE
In which only the terms will not be during the journey of the lovers of water tourism! And not always the boat suitable for sailing in a pond, suitable for another. We have...