TubeNet

Alt URL: http://www.ebay.co.uk/itm/Besson-Valve- ... 0805547256" target="_blank

I have one of these it came free with a tuba while they may keep your lap dry if you store your tuba on its bell you will end up with brown spots on your bell like I did.
I can see how they may have some use but can't see it being worth over a £100.

Having used in the past on my old 981, these are best used with something adsorbant, like piece of sponge inside to collect the drips to avoid emptying when turning the tuba.

Wessex Tubas from July will stock this type of grime gutter, selling for only £25 in UK, or $30 in USA - so if required, you can save money!

The something absorbent that I used was a Tampex in the gutter worked well until it swelled and sealed the vent and slowed the valves I have gone back to using a rolled up microfiber cloth dry lap and something to polish with when idle.

If you can't find the inserts that DON'T swell, try using a piece so chamois rolled up or folded. That works pretty well.