MagnaTrack Starter Kit balances design and comfort with organization to personalize your workspace. The included 4 bars are made of durable, sleek steel and have a strong adhesive backing. Simply place them on the edges or underside of your desk depending on which magnetic accessories you want to use. Each steel bar holds up to 3 lb. Bars work with most magnetic accessories (not included). Bring your own or expand with MagnetPlus products. Change your setup as often as you like.