If you have any interest in masturbation, and toys to help in this activity, you'd have to have spent the last few years under a rock to have missed the revolution that is Fleshlight (also known as Fleshjack).
The toy itself is a plastic tube, discreetly disguised (kind of) as a torch or flashlight. It has a screw-on cap and one of any number of styles of inserts within. Inserts can be bought separately and changed for different sensations while stroking. There are now so many it's hard to find one place that sells them all. There are different colours, different orifices, different cases...
And now to some examples of how guys use them.