I searched TRK502 to see what came up and found this thread. Only as I have one.
Very pleased with it and no quality concerns. It was between a three year old Japanese bike or a brand new Benelli. No regrets.
I’ve found using a sanitiser in my helmet interior and that kills the bacteria that creates the smells in the first place. The stuff I have is by Diomyx and works a treat.
Also use it on my stinky trainers! Keeps the Mrs happy