those little rubber tubes in puncture repair kits.

What the **** are they for?

Woods valves

castrating lambs

Probably to be used in conjunction with treadstop compound

To explain, a Woods valve is a very early one that has a long needle-like bit that has a hole in it. The tube fits over the needle covering the hole and when pumping up, the air squeezes past the rubber tube into the tyre. However, when the pumping stops, the pressure inside the tyre forces the rubber tubing over the hole to seal it up.

Air is released by turning a knurled screw and loosening the whole valve assembly.

The reason the tube is in the kit is that with time, the rubber used to deteriorate and let the tyre down.

and when was the last time anyone actually used the tube, for what its intended for?

I had to use a new one the other day, a mouse had ate through my tyre tread and after I had used the trusty Treadstop to fashion a new tyre tread, I struggled to inflate they tyre, luckily my patch kit had a new woods valve tube in it, and despite being a patch kit from 1923 it was a s good as new.