SolarCharger has a 3 to 4 digit weight designation system.

The 1st Digit is for weight except for Nord, which has the first 2 digits used for weight.
(5 is Regular, 7 is Bold, 9 is Black, 10 is Nord, 1 is Hairline, 3 is Light).
The following 2 digits are for italics (50 is for Vertical, 52 is for italic).

Examples are below;
152 is Hairline Oblique
1050 is Nord
550 is Regular