This furniture feet levellers are great addition to your home! Easy to install, they offer adjustable height to suit your needs. With these feet levelers, you won't have to worry about wobbling furniture on uneven flooring, as they help to reduce vibrations and noise while moving furniture. Step 1: Sign the height youwant on the drill bit. Measurement: Ensure that you have the correct measurements for your furniture legs. Measure the hole diameter of the leg where the T-nut will be inserted. Step 2: Drill a diameter 0.37" (0.93mm) hole into the furniture on the right plece. Pre-drilling: It's generally recommended to pre-drill a 0.37" (0.93mm) diameter hole for the T-nut. This helps prevent any splitting or damage to the furniture leg when installing the T-nut. Step 3: Fix the T-nut into holewith a hammer. Insertion: Carefully insert the T-nut into the pre-drilled hole, making sure it is aligned properly. It may require some light tapping with a hammer to secure it firmly into place. Step 4: Screw the leveler in andadjust the height as you like. Alignment: Before installing the leveling feet screw, ensure that the T-nut is properly aligned with the threaded hole in the furniture leg. This will allow for a smooth installation and proper leveling of the furniture. Wide Application： Prevent direct contact between the furniture and the floor.Install levelers on the furniture to easily move it when cleaning.The furniture is unbalanced and shakes during use.Want to increase or adjust the height of the furniture. NOTE: If you receive the wrong quantity or size of the adjustable furniture feet, we will help you within 24 hours. How big hole should I dril or what drill bit size is compatibel for 1/4" -20 UNC? Pre-drilling: It's generally recommended to pre-drill a 5/16" (0.31",0.78mm)diameter hole for the T-nut. This helps prevent any splitting or damage to the furniture leg when installing the T-nut. What size hole should I dril is compatibel for 5/16"- 18 UNC? Pre-drilling: It's generally recommended to pre-drill a " (0.37",0.93mm)diameter hole for the T-nut. This helps prevent any splitting or damage to the furniture leg when installing the T-nut. How deep will be drilled? Depth: When pre-drilling the hole, make sure to drill it to the appropriate depth to accommodate the T-nut. There is detailed specification in installation picutes. Is the black base removeable? No, the black base and the screw are integrated,will never separated easily.It can be used for very long time. Is the black base hard or rubber? Hi,the black base is plastic,I think the soft rubber is easy to be worn.Beacause I had bought rubber ones used on my kitchen chair on Jan,,but worn out only for several months.I will try these palstic base.