The RAM® Slide-n-Lock™ 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)