I have never used an U/S on a snake only materials and not very much of that. The ones I have worked with are not as easy as it seems it is likely that you should factor in the cost of training (friendly RVT maybe...) on top of the unit. There are a handful of USB wands out there now that don't seem super expensive (under 5000) I have not had one in my hand to know if it is worth anything or not. Most bigger units are over 10000. My understanding is follicles are only noticeable by hand at 3/4 inch basically at the moment pairing needs to happen a U/S gives more precision as they can be checked as they develop. I am just repeating what my research has come up I have never done it myself. I have only U/S metal for flaws.