Old casting ruler, yellow or potato color to some, with light veining. Standard measurements from 4.5-5.5 mm. God willing, it makes two rosaries of 150 beads or 3 rosaries of 100+ beads. It's best to calculate it with your drill bit, as it varies from one drill bit to another. The best drill bit for rulers is Al-Asemah Workshop. No one should look or contact unless they are serious. Thank you ❤