This might be retarded question:

My bicycle tube size is: 26x1.75/2.125

Does 1.75/2.125 part shows the size range, as the tube will fit the tire sizez between 1.75 to 2.125?
If I am mistaken to understand the meaning of those two numbers, would it be ok to buy a tube sized: 26x1.90/2.125?

Thank you for you help.