Casio EF-521D / EF-521GF Manual — Modules 5026 / 5138

Two owner's manual PDFs for the Casio module 5026, each a different scan (English included). Casio fitted it in the EF-521D and EF-521GF. The same documents also cover module 5138. For module 5026, Casio's spec sheet lists one SR626SW, with 2 years of battery life and accuracy within ±20 seconds a month; the module first shipped in Nov 2007.