http://www.aosong.com/en/products-32.html
Official Datasheet (EN): AHT20-AM2108_A4.pdf
Lib: https://github.com/Thinary/AHT_Sensor
See some test results:
Test 2 v9 new sensors overview
Test 3 v10a high to low humidity
Test 1 v10b humidity absorber
Test 5 v10b NaCl solution draft