Avoid Castrol Response Brake Fluid!
 

I recently purchased Castrol's Response brake fuid from Halfords to find there was no air-tight seal on the bottle!

I returned to Halfords thinking I bought a duff bottle, but no! All bottles had no air-tight seal. This is DOT-4 fluid, so it does absord moisture from the air.

This makes the fluid absolutely useless, so check carefully before using.

Ben