EF-2100 - Product Brochure ALPHA EF-2100 provides the highest activity of any VOC-free Bellcore SIR compliant flux for defect-free soldering. This flux is formulated as a direct replacement for ALPHA EF-2210, ALPHA EF-2202, ALPHA WB-400 & ALPHA NR-300. Alpha EF-2100 - Product Brochure