Uprights are the vertical frames that you connect your load beams on to make a rack. There is one on the left and one on the right. There are 2 sets of holes punched side by side on the upright. This allows for the pallet racks to be linked together to make the row of racks as long as needed. The teardrop holes are spaced every 2″ apart top to bottom and run the entire height of the upright. This provides room to adjust your beam levels up or down in 2″ increments.Heavy duty uprights usually have a 5″ x 8″ x 3/8″ steel footplate welded to the bottom of each leg. The foot plates will have either 2 or 4 holes punched to allow the installation of anchor bolts to secure them to the concrete floor.