Anti-fluid tape for extender use

I have unfortunately finished my roll of anti-fluid tape provided by Monkeybar. Does anyone know where I can purchase this domestically (UK)? Or what I should be looking for?

Ive tried using surgical micro-porous tape but it fails to keep a good seal and the device easily slips off. Without any tape I quite quickly get fluid build up too :S

Any help would be great,

Luke.