This Basque Rosary pendant is designed after the Rosary ring (which typically has a hole in the center for a finger/thumb). 1.25 wide by 1.5” tall. Sterling Silver.

10 'AVE' KNOBS 
What is a 'Basque Rosary Ring' or a 'Thumb Ring'?  It is a flat ring with 10 prayer knobs, rosebuds or notches for the Ave's (Hail Mary). The Pater (Our Father) is prayed on either a cross or symbol at the top.  To complete the 5 decades of the rosary, the Thumb Ring is moved from one finger to the next. 

Source: http://www.rosaryworkshop.com/