The SIRUI R Series tripods are excellent entry-level tripods.They're ruggedly built and offer many desirable features.The specially designed Center Column Locking Collar is very convenient to use - even while wearing gloves in cold weather. To adjust positioning on uneven surfaces, the SIRUI R1 and R2 have two leg angle positions. And the SIRUI R2 has retractable spikes for greater traction outdoors. The Center Column can be inverted, for close-up photography or shooting at unusual low angles.And the tripod mounting plate comes with a double headed, reversible screw that accommodates 1/4" and 3/8" tripod sockets. To make horizontal alignment fast and easy, a built-in bubble level is included. SIRUI R Series tripods are available in economical Aluminum or lightweight Carbon Fiber.