For metal post installation, specifically for Rolled Edge Vertical Line Posts.
Comes with two nuts. If you have wood posts, use screws or lag bolts.
If you don't know what type of T-Posts you have, weigh one and divide by the number of feet to get the pounds per foot. If they are already in the ground, you might just need to get both sizes to make sure you have the u-bolts that will fit.
To find out what type of u-bolt you need, weigh the post and divide that weight by the length and that will give you the type u-bolt you need.
If you are attaching u-bolts to a t-post, you will need either the 1.25 with an inside dimension of 1.5 inches, or .85 to .95 with an inside dimension of 1.25 inches.