In the 20-gauge FLEX TLS, Mossberg has delivered a tool-less, modular, lower-recoil Model 500. It has proved it is indeed worthy of taking its place next to the original Mossbubba 500—and dare I ...

In other words, you can make some child elements flexible and others fixed, which makes for considerably more complex layouts using only a fraction of the code you'd need to do that using pure CSS 2.