These ring sizers are available to measure UK/ Australian sing sizes. They are helpful in determining your desired ring size and are able to be used on different fingers for determining different sizes. To use, simply form a circle by wrapping the end of the sizer through the gap where the arrow is. Then simply place the loop on your finger and tighten the end until comfortable. The sizer shouldn’t move around too loosely or fall off, on the flip side it should not be too tight and should be able to be removed with ease like you would a ring.