Of course I had to Google to find out what other things we export.
America's exports to China amounted to
$116.2 billion or 7.7% of its overall exports.
  1. Aircraft, spacecraft: $15.4 billion
  2. Electronic equipment: $12.8 billion
  3. Machinery: $12.3 billion
  4. Oil seed: $11.1 billion
  5. Vehicles: $10.9 billion
  6. Medical, technical equipment: $7.9 billion
  7. Plastics: $4.9 billion
  8. Woodpulp: $3.4 billion
  9. Organic chemicals: $2.5 billion
10. Cereals: $2.4 billion
Top US Exports
On another site it listed Washington as the number one state exporting to China in 2014. 
US State Exports to China (2005-2014) | US China Business Council
That's a lot of ProVaris.