Stk411-210e Datasheet [extra Quality] -

This IC is a “hybrid” module, meaning it combines multiple discrete components (transistors, resistors, and diodes) on a ceramic substrate, all housed in a single insulated package. This design approach offered manufacturers a balance between the performance of a discrete component amplifier and the convenience of a monolithic IC.

Access technical diagrams and pinout charts for the broader STK411 family on Stk411-210e Datasheet

Yes, some later production runs of the STK411-210E are labeled as and RoHS compliant (Restriction of Hazardous Substances). This IC is a “hybrid” module, meaning it

The “E” suffix likely indicates:

The ZIP-22 layout splits inputs, power rails, and outputs to minimize crosstalk and electromagnetic interference (EMI). This IC is a “hybrid” module

Left and Right channel signals are sent to the input pins through coupling capacitors to block DC.