Marianne
Good 'core' module for training needs
This is the module I use for most of my training needs, particularly when doing deadhang repeaters. If you're getting a mixture of warm-up modules and more challenging ones, 30mm is a good intermediate edge depth and the 5 degree angle of the Slot 30 (it's not a flat edge) means you're actively holding the edge and working a tiny bit harder to stay on it than if it were a flat edge.