My friend is a long-time nurse, recently went back to school for NP degree and will be finishing up at the end of the year. I'd like to get her a new stethoscope as a gift. The Littmann website has so many to choose from and I'm not sure which one to get. I want something high quality but something realistic as far as what she'd really use it for. I'm sure something light weight would be better, but is the "triangle shaped bell for listening under blood pressure cuffs" really far superior to a normal round bell if the price is really alot different? Is there a standard length not to go under? She will likely be working more with adults but I'm sure something that would work with kids would be handy as well. Thanks for any tips!