The A-Frame Base Cart This A Frame Slip Fit Base Cart is one of our most popular carts. It Stores and Transports our Slip Fit Bases with stacking slots (which are standard on all but our Heavy slip fit bases). The dimensions are: 30? W x 48? L x 56? H, 299lbs. Painted in a Silver Veined Powder Coat, our Slip Fit Base Cart holds 100 Large or 150 Small Slip Fit Bases.