Shelf Clips - Shelf not included (Silver) (4"D x 2 3/4"H x 3/4"W)

i had purchased this to install a 12" deep shelf , if you cant screw it to a stud ( i used a toggle bolt) & the shelf is deeper than 8' and if the total weight is more than 20 lbs this bracket will not hold the shelf horizontal . it will tilt forward. use for light objects only. it has only one screw per bracket that too not easily accessible , needs a long driver extension. a second screw would inspire more confidence.

dont want to waste money on returning