RAM base mount. 9 inch by 9 inch weighted base. Heavy enough to support an LCD monitor. Hole pattern works with 3.68 inch D202 with D style 2-1/4 ball or 240 with C size 1-1/2 inch diameter ball. 3.68 inch diameter base with C size 1-1/2 inch diameter ball. RAM universal mount system. Lifetime Warranty.