shelving: spacing of rails?

How to Install Twin Slot Shelves in a Shed twin slot shelving spacing ensure the spacing between the shelves suit your needs 10 SAFETY FEATURE: Drop-and-lock bracket design prevents the bracket from accidentally being twin slot shelving brackets I've just found some spur shelving info and the recommended screw size is a 12 gauge twin-slot shelf uprights and brackets

twin slot shelves Watson Lok Twin Slot Shelving; 270mm White Bracket; 10 Pack; When fitted correctly in normal conditions, the system is guaranteed for two years