410-1Kg Ammonium Persulphate

https://www.mgchemicals.com/products/circuit-board-design/copper-etchants/pcb-etching/

410 Ammonium Persulphate is a copper etchant compound used as an alternative to traditional ferric chloride to produce a cleaner copper etchant solution. One kilogram of ammonium persulfate mixed with water will produce four liters of etching solution.

Features & Benefits
Transparent solution allows visual inspection of the etching process
Compatible with tin etch resist
Non-staining solution
CARB compliant