Constructed from anodized aluminum, the 2120-00 adapts 3-1/2" x 8 tripods to 5/8" x 11 instruments. Weighs 0.7 lb.

Helpful Tip: If you're curious about thread sizes and what the size dimensions really mean, it's really simple once you understand them. Let's use a 5/8" x 11 thread size since thats the most common size thread used in surveying equipment instruments, tripods, and adapters in modern surveying. First keep in mind that threads have a crest and a trough. The first dimension is the diameter of the shank from crest-to-crest. Then, the second dimension is the number of threads in any given 1 inch of shank. So, a 5/8" x 11 is 5/8" in diameter and has 11 threads per inch of length. Even if you don't have a full inch of stock material, the number of threads per GIVEN inch of material still applies. If you think about it, 11 threads per inch is rather coarse, and 20 threads (as in 1/4" x 20) is almost double the amount of threads per inch of stock material. Hopefully this explanation of thread size dimensions helps you understand what you have and what you're looking to adapt to.