Advantages of our Free Hanging Floating Shelf Bracket Heavy Duty Design : both the vertical and horizontal part of brackets are made of 3/8” thick steel to guarantee maximum load capacity. Hidden Floating Support : the free hanging countertop support bracket remain discreetly hidden beneath your countertops or shelves, offering a modern and uncluttered appearance. Easy Installation : all our floating shelf brackets come with screws included.With pre-drilled holes and straightforward instructions, you can easily install these brackets yourself, saving time and effort. Different Size and package : our heavy duty shelf brackets comes in different size and packs offering most valued investment choice for you. How to Determine the Size to Use: When determine the length of the bracket, for example, if you have 16 inch wide shelf, you would stay 2-3 inches from the outer edge, plus the 3 inches inside the wall. Then 16 inches minus 2 inches plus 3 inches equals a 15 inch shelf bracket. How to Determine the Amount of Bracket to Use: When using this floating bracket for shelves less than 100lbs you can space these brackets on every other wall stud. When using this floating bracket for Bars, Countertops, Benches, Cabinets, or Vanities you will want to use (1) bracket on every wall stud which would be (1) bracket every 16" or 26" depending on the framing method used.