For selection of stainless steel crown, which of the following is not the criterion?
Three main considerations have to taken care while selecting SS crown for pedo patients:

Mesial distal diameter
Light resistance during seating
Crown height

Before preparation, use Boley's gauge. After preparation, trial and error method should be followed.
Smallest crown is selected. Friction should be felt, when crown is slipped gingivally.
Mesial distal diameter
Light resistance during seating
Occlusal morphology
Crown height