Heat shrink sleeving is, as the name suggests, plastic sleeving which shrinks when a moderate heat (a hair dryer is hot enough) is applied. It is used to cover joints in cables, and to provide mechanical reinforcement over the ends of crimp connectors, among other things.

It is very easy to use. The only trick is to remember to put it on the cable before you join the other cable or component to it - otherwise you'll have to undo the joint and start again.....

Heat-shrink sleeving has been available for some years, but was not always around. Previously people used rubber sleeves stretched with Hellermann pliers¹, a bizarre three-pronged tool over which the rubber sleeve is stretched. Alternatively, electricians' tape may be used - although this is not recommended for permanent installations as it tends to come off with heat and time.

Heat shrink is so easy to use, so cheap and so useful that every DIY toolkit should contain some. It is much safer (and therefore better ) than the ubiquitous gaffer tape for insulating cable joints and soldered connections, and it has several uses under the bonnet of a car (including emergency repairs to windscreen washer hoses).

So pop out to your local electronics shop and buy a few bits in assorted sizes. You never know when it might come in handy!