White Power was originally Dutch, and supplied many marques with hi-end suspension, amoung them Zane Laverda. Now owned by KTM.
Rumour has it that YSS evolved from the (also) dutch Technoflex suspension manufacturer when they closed in 2010, with tooling moved to Thailand. TFX is a dutch company founded by former Technoflex employees in 2010, following on from where Technoflex left off. Technoflex were well known for their high quality stuff, I do not know what led to their demise.
I've found YSS build quality to be at least equal with the best of their direct competitors and incorporating lots of modern technology, making IKONs look seriously dated.
piet