Brymen BM839 User Manual page 14

Battery and Fuse replacement
Battery use: Four 1.5V AA alkaline batteries (IEC LR6)
Fuses use:
Fuse (F2) for µA/mA input:
0.4A/1000Vac & Vdc, IR 30kA, F fuse; or better. Dimension: 6 x 32 mm
Fuse (F3) for A input:
11A/1000Vac & Vdc, IR 20kA, F fuse; or better. Dimension: 10 x 38 mm
Battery and Fuse replacement:
Loosen the screws from the access cover of the case bottom. Lift the access cover.
Replace the batteries or fuse. Re-fasten the screws.
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