The difference is outside plating and the material of rubber for waterproof.
Part number
Plating
Material of rubber
LF10WBR-C
Nickel
Silicone (Black)
LF10WBR-C(03)
Black chromium
Silicone (Black)
LF10WBR-C(31)
Nickel
Acrylonitrile-butadiene rubber (Gray)