The Bloc shelf clip is adjustable to work with nearly any shelf material ranging anywhere from 1/4 in. to 3/4 in. thick. When paired with a shelf measuring 8 in. or less in depth, these brackets can support up to 33 lbs. One of the smallest shelf brackets, Bloc is a great compliment with glass shelves for a minimalist look and feel. Bloc small size helps give the appearance of floating shelves. in. The Bloc shelf clip set comes with 2 brackets.