The 1-7/8" is referring to the overall length of the socket and shaft.
1/4, 5/16, 3/8 & 7/16
At work we use duct seal to get the shavings out of the nut drivers. Its like a putty, you just smoosh the nut driver into it and the shavings will stick to the duct seal. then you tear off that piece and throw it away. A 1 pound brick of duct seal is around $3
The model # 49-66-4562 is on the Home Depot web site. These are 1/4,5/16,3/8&7/16 by 1&7/8 in length. I have a set and I’m well pleased with them . Hope this answers your question.
The size of the nuts they fit are specified on the driver.