These Ski's are sold in pairs, They are designed to fit on top of your spot board stands ( Sold Separately ) You can use these with set up with another spot board stand ( With Ski's on) to support 2 scaffold boards, they have screw holes in to secure your boards. You can then use these as a hop up or more commonly to stack your bricks on to bring them up to a easier working height.
You will need 2 per spot board stand