Does a 'short tube cover' exist?

I've never used tube covers as I have a heated tube.
However, since I started using the AirFit F40 recently, I'm occasionally getting a little rainout. Condensation is forming in the short tube supplied with the mask, now that the outside temperature is dropping. Is there a short tube cover available for this? Perhaps people make their own covers?
I'm assuming that it's not a good idea to cover the whole length of tubing if there's a heated tube fitted.

I'd be interested to know your solutions or suggestions for this.

TIA

Thanks Pugsy,

Rather expensive as it doubles in price with UK shipping.
Is it ok to use covers on ResMed heated tubes, or will they overheat? I could just buy a long one.

I have used a hose cover (one of Padacheek's) for years on a heated hose without anything overheating.
All that happens is you end up using less electricity to maintain whatever hose air temp you end up selecting.

If the price of a short hose cozy/cover stops someone.....use what I used before I sprung for a store bought hose cozy.......
Just get a tube sock and cut out the toe and slide it over the short hose and secure with a rubber band or bread tie.
It's easy to make your own and not have it cost all that much.

Thanks again, that's good to know I'm not going to suddenly combust in my sleep

I shall likely buy a 2 metre one, which will cover most of the heated tube and all of the F40 extender.