These thimbles from PRYM are great to use when you're doing a lot of sewing, or when sewing through slightly thicker fabrics. They fit well and are easy to use and maneuver. They can be worn on the ring finger or middle finger; it's a personal preference. There are many types of thimbles, but these are the best I've tested so far!
They come in three sizes. For me, S works best on the ring finger and M on the middle finger. The measurements are as follows:
S: length 2.4 cm, diameter 1.4 cm
M: length 2.5 cm, diameter 1.6 cm
L: length 2.7 cm, diameter 1.8 cm