pH51
Waterproof pH Tester with replaceable electrode

pH52
Waterproof pH / Temperature Tester with replaceable electrode (0.1 pH resolution)

pH53
Waterproof pH / Temperature Tester with replaceable electrode (0.01 pH resolution)

C65
Waterproof Conductivity Tester with replaceable electrode (low range)

C66
Waterproof Conductivity Tester with replaceable electrode (high range)

T75
Waterproof TDS Tester with replaceable electrode (low range)

T76
Waterproof TDS Tester with replaceable electrode (high range)