Current Walbro and Zama carbs are often made in China to Walbro and Zama specs.

There is a Chinese copier of Walbro carbs (brand name EMAS) that has a fair record but you rarely see the EMAS name or even a model number on them.

The Chinese are quick to copy a successful name brand but not too good on supplying the spare parts. To correct that statement, they actually do make some spare parts and in particular the diaphragm kits but they label them under the pretense of being replacements for specific Walbro or Zama carbs. The Stens after market company imports mostly Chinese parts.

So be careful about repairing your Walbro carb with new diaphragms that you are getting genuine parts?

Newer carbs come with brownish Kevlar or bluish Mylar pump diaphragms which rarely go bad but the metering valve diaphragm is still the old style "rubber" and will eventually get stiff.