Yes, the Big Ball Marker is a legal

Big Ball Marker dimensions vs Rules of Golf:

• Height: 22mm  (ROG allowable is 25mm) - Legal
• Width: varie, but always less then 50mm (ROG allowable is 50mm)- Legal
• There is no measurements of slope, speed, wind,.......- Legal

 

*Always check with a tournament offical before using it for competition, as all tournaments can make their own rules.

**Now your weekly golf buddies may think it is too big, but it fits into the rules of golf