Array
(
    [kg] => Array
        (
            [wcd.title] => Kilogram
            [wcd.unit] => kg
            [weight_class_id] => 1
        )

    [g] => Array
        (
            [wcd.title] => Gram
            [wcd.unit] => g
            [weight_class_id] => 2
        )

    [lb] => Array
        (
            [wcd.title] => Pound 
            [wcd.unit] => lb
            [weight_class_id] => 5
        )

    [oz] => Array
        (
            [wcd.title] => Ounce
            [wcd.unit] => oz
            [weight_class_id] => 6
        )

)
Array
(
    [cm] => Array
        (
            [length_class_id] => 1
            [lcd.title] => Centimeter
            [lcd.unit] => cm
        )

    [mm] => Array
        (
            [length_class_id] => 2
            [lcd.title] => Millimeter
            [lcd.unit] => mm
        )

    [in] => Array
        (
            [length_class_id] => 3
            [lcd.title] => Inch
            [lcd.unit] => in
        )

)