Over-inflated Tires. Tire tread wear in the center of the tread pattern tells you that the inflation patterns are too high. Too much pressure can cause the contact patch to shrink and the center of the tire to carry the entire load. Under-inflated Tires.
Apple Products and Services. Most Thunderbolt hubs won't work. In fact, I'm not sure if any will work not. (I've never been in a position to try this with a MacBook Air.) I found several instances from people who thought it would, bought a Thunderbolt hub, then found out it wouldn't work. The best way to do it, is to plug one monitor into the Thunderbolt port and another one into a USB port. To do this you will need the appropriate adapters. What adapters you need depends on what kind of monitors you are hooking up, and what ports they have. According to Apple, you can hook up a total of two external monitors to a MacBook Pro. Written Sep 25, 2015.
The w2207h monitor has 2 USB ports on the side. It utilizes a standard USB cable to complete the hub. The cable plugs from the rear of the CPU to the monitor. Physically it adds convenience of 2 USB ports at the monitor, using up 1 of the CPU's rear USB ports.