Originally made in the Philippines. Later, Simmonds (which is a brand, not an actual manfacturer) had them made in China. The earlier Philippine ones are generally reckoned to be better, and so cost more. I do not know how you tell them apart, unless the box or papers say "made in X".
I have a Filipino one, about 15 years old. It's nice. Never spent time with a Chinese one, so can't say whether it's worse and if so how much worse. Some Chinese stuff is quite decent.