Premium = Lithium Ion battery + two ophthalmoscopes
Enhanced = NiCad battery + two ophthalmoscopes
Standard = NiCad battery + one ophthalmoscope (the Coaxial Ophthalmoscope, not the PanOptic Ophthalmoscope)

The LiIon handle is smaller, lighter, more nimble, faster to charge, and much better rechargability.

For the NiCad models, you can swap out the included battery, and stick in 2 C-cell batteries with a converter ring (included), otherwise it takes hours to charge.

Both models have a removable charger which sticks into an outlet, hanging out of the wall.

The NiCad handle is much heavier and heftier; and only the NiCad has the c-battery option.

Either the premium or the enhanced are great options for medical or veterinary students, or home users. e.g. to check your kids ear infection progression/severity, or your retinas. The manuals are lousy. They expect you to know how to use the tools.

These are also suitable for home consumers who want real tools: the Welch Allyn oral thermometer Welch Allyn 01690-200 Suretemp Plus 690 Electronic Thermometer Oral Probe With Oral Probe Well or the home blood pressure monitor Welch Allyn Home 1700 Blood Pressure Monitor with SureBP Patented Technology and Simple Smartphone Connectivity - H-BP100SBP are great additions to your home if you want professional-grade, reliable measurements.

Most people know the name Welch Allyn just from going to their doctor getting a physical. This set, which is the Premium Diagnostic set, features all of the bells and whistles for a professional or a student in training. It comes in a flexible carrying case that is designed for the doctor to take with them. While it is small and compact, it seems strange that such high end medical devices seem kinda crammed in a low quality carrying case. The pieces kinda overlap each other and dont necessarily fit snug, like you would think or perhaps even want. Thats my first impression when I opened it. But this does not take away from the pieces that comes with it, as they are all high end materials used to make them.

The set comes with a main stick that each of the pieces can attach itself, thereby powering the individual devices. There are a few ophthalmoscope heads that helpsdetermining the health of the retina, and optic disc. You also get an otoscope which helps look into the throat and especially the ears. The entire set is lightweight. A lithium battery is included. Overall, if you are starting a practice or beginning work as an ophthalmologist, this is perhaps the best set you can get and would come highly recommended.

This was great to get. I love this and have wanted one for a long time just so that I can check my son's ears if he is having issues. I love that it comes with ophthalmic accessories. Everything worked well and turned on as soon as I opened it. I have not figured out to charge it as of yet.
I will update as I continue to use it.

I received this for my honest opinion and was not compensated.

Top of the line set complete in one case. Yes it's pricey but this is a set for any medical student or beginning practitioner that will last a lifetime if taken care of.

The best company is Welch Allen