The accessories you need will be sent in the package box(four extension screws, four standard screws). 【EASY ASSEMBLY】- Installation is quite simple and only requires a couple of tools. Antique & Vintage Style Brackets for Heavy Shelving & Cisterns Made From Solid Cast Iron.After assembled, it can be used as a bookshelf, kitchen shelf, exhibition stand, garden shelf, external wall bracket, garage shelf, etc. HEAVY DUTY 3/8 inch thick Hidden countertop brackets PERFECT 90 DEGREES Made by PRECISION ROBOTIC Rated to support 150 pounds per bracket Use on Quartz. CAPACITY (BRACKETS) 90 LBS on 12' deep Shelves. Our brackets including mounting instructions as well as lag bolts for heavy loads. LENGTH IS THE LENGTH OF THE BRACKET BODY PROTRUDING FROM THE WALL ONCE INSTALLED. The long side of the bracket (100mm) is fitted against the wall. Ideal for use with any length shelf with a maximum depth of 150mm or for bow fronted shelves as featured in cross selling products. 【COMPATIBLE PLANK SIZE】- This kit is compatible with shelf width ranges from 8.5" to 11". When installed correctly, our shelf brackets can hold approximately 75 lbs. See our quality shelves by clicking on cross selling products that can be fitted using these brackets.They can hold things stably and never drops off. 【450 LBS LOAD BEARING】- The steel shelf brackets can work together to support up to 450 lbs load.They are crafted with the varnished baking surface for classic look and anti-rust. 【HIGH-QUALITY METAL】- Amount: 2 Pack Color: Matte Black Product Size: 8x9x2.5" The floating shelf bracket is made of high-strength steel, which is reliable, sturdy & durable.