What is Reddit's opinion of osea 5L/1.3 Gallon Portable Water Tank, Storage Plastic Jug Cans Spare Emergency Backup Tanks Mount for Motorcycle SUV ATV Most Cars (Red)?

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So... The gearhead brigade is really not going to want to hear this but I have had excellent luck over the years with knockoff "Rotopax-esque" tanks. I have two identical to this one and I have had zero problems with them. Obviously they're not compatible with real Rotopax mounts and accessories, but if you don't care about that they're an excellent deal.

I have always found the name brand Rotopax cans to be incredibly overpriced for what they are and as you've experienced (unless you unknowingly got a counterfeit or something) that expense does not necessarily translate into good fit and finish.