This kit comes with everything you need for your project.  Each kit comes with:

• (4) 1/2" diameter standard caps 
• (4) 1/2" diameter x 1/2" tall barrels 
• (4) Connecting studs for material up to 1/8" or 1/4" thick
• (4) Combination screws for mounting to drywall or wood 
• (4) All-purpose nylon anchors