Both the main case and the laptop carrier are as sturdy as a turtle shell, providing sure protection for your computer, PDA, camera, toothbrush and underwear.
(Both the main case and the laptop carrier; are; as sturdy as a turtle shell) (PDA; [is] computer [of]; yours)
Both the main case and the laptop carrier PDA
are [is] computer [of]
as sturdy as a turtle shell
yours