I wear a size medium Dura Glove and also a size medium Safari Tuff 3 under tab. My hand is a tight fit in the Dura Glove until I have shot it for a while and it has stretched to fit.
If you’re not used to a tab, the correct size may look too small to you at first. With your fingers extended, a good 1/4-1/2” of fingertip should be exposed over the top of the tab. This tab is designed for a deep hook, where you start with the ridge on the tab pressed against the bowstring, which should make the string fit exactly in the first joint of your fingers. If you release correctly, by relaxing your fingers, there should be no bowstring-finger contact. If you try to open your fingers instead, you might notice a sting. Consider it a learning experience.
This is the best tab I have ever used. Other similar tabs are not only too long but also too wide, which interfere with a clean release. The width of the tab should not extend beyond the width of your three fingers held together.