The GC ELECTRONICS 21-169 is a positive pre-sensitized phenolic circuit board ideal for hobbyists and professionals alike. Its 1/16" thick phenolic base provides a stable foundation for circuit design, while the one ounce copper layer ensures reliable conductivity. The positive photo etch resist coating simplifies the etching process, allowing for precise and professional-looking circuit boards. Compatible with GC Developer solutions, this board meets Fed. Spec.: S-10941-1 and is a versatile solution for a wide range of electronic projects.