The net weight is the total parent product (kit) weight from the Products page.
The gross weight for the hazardous materials is the total parent product (kit) net weight from the products page plus the total subproduct net weight from the components page.
The second gross weight is for the non hazardous materials (non regulated materials). This is just the net weight for the non hazardous and does not include the net weight for the parent product.
See video
https://drive.google.com/file/d/1RIoD_zPuARAvBwJIBAs13jqtp5i5BQsS/view?usp=drive_link