Leigh bench hold downs?

[Don Wacker]

Does anyone use the Leigh bench hold downs. What I'm wondering is what size is the key hole? I'd like to be lazy and use the Leigh instead of the Kreg. The Leigh are round and the Kreg are rectangle.

Thanks
Don

[Peter Stahl]

Here's a link to the mounting instructions, the drawing looks to be close to scale.

http://www.leighjigs.com/Surface_Clamp-Instructions.php

[Jim Matthews]

What do these cost?

I'm using the Veritas hold down, and it fits into a 3/4" round dog hole.
I tried the Jorgensen cast iron hold down, which is a powerful screw clamp, but the through bolts are a chore on my bench.
(With a cabinet underneath.)