[Muti-purpose]Adjustable Mast to Mast Mounting Kit offers even more versatility, great for mounting torches,flagpoles,umbrellas,radio/tv antenna and other outdoor decor. [3 Kinds of assembly]The antenna mast clamp is great for mounting round pipe() to another round pipe(), square railings to another square railings,or mounting round pipe() to square railings.(The diameter range of round pipes is 1 - 1.8inch, the diameter range of square pipes is 0 - 1.8inch). [V blocks more stable]Heavy duty mast mounting clamp uses blocks with two long bolts(2.2 inch in distance,5.49 inch in length) to give a stronger install for ensuring the patio umbrella not slip down. [Sturdy construction]Antenna mast to mast clamp kits are made of strong,durable galvanized steel,durable and designed to safely hold your patio umbrella. [Easy to install and move]Outdoor Umbrella Holder Comes with 2pcs small wrenches,no need other attaches to decks, balusters,railings,or pipe quickly and securely. Colour: as shown Material: Alloy Size: About 15x7cm Contents: 2 * Double Antenna Mast Clamp 2 * Small Wrenches Only the above content, other are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.