![Image](https://i.imgur.com/kxwPBzY.jpg)
I have had one, filled with water and hanging off the washing line for the last week to check seam strength and proofing and can report back that it does what it supposed to.
Made by NGT and with a price tag of around £7.00 it was worth a punt.
10" diameter, 8" tall and squishes flat when empty.
Will use it and report back if it springs a leak!