The RAM Slide-n-Lock&trade allows you to quickly connect your VESA Plate mounted monitor to your RAM mounting system, and then LOCK it in place. The top plate has the universal 75mm and 100mm VESA hole pattern, while the bottom connection has an AMPS hole patten. A RAM ball is not included with the purchase of this product. The recommended ball size system for Monitor mounting is the RAM-202 (1.5" C Size Ball)