If you look at the second pic, the bottom of the ratchet has a 17mm hex portion. You place the socket in a 17mm ratcheting wrench to create an ultra low profile ratchet/socket combo like the third pic.
I ordered the large wrenches and took a chance on the $20 back in points. I got them a day later and used them to buy the craftsman tappet wrenches and the multimeter that where on sale.
I got the 20/8 metric set and 20A/6 sae set for $152 shipped to CA from Amazon.de. You just go to Amazon.de go to the bottom and change the language to English, search for stahlwille 20/8 and when you find it click on the sold by other sellers and select Amazon as the seller. I have Amazon Prime...
I think autozone rents this in the loan-a-tool program https://www.amazon.com/OEMTOOLS-27035-Coil-Spring-Compressor/dp/B003A18KCQ/ref=sr_1_20?s=automotive&ie=UTF8&qid=1474083425&sr=1-20&keywords=spring+compressor
or there is this...