I have an 05 Heritage. My stock tire size is 150/30R16. I am looking at new tires and want to know what size will fit on the rear. I don't necessarily want to go bigger, but everthing I look at online has different size descriptions. They are the same except for the 30R part. Is it all the same as long as the 150 and the R16 are right?
What does the the 30 stand for?

Thanks for your help, Ron