The Flex Inner belt offers some features not found on other inner belts - a rear flex/expansion panel, and internal storage. The rear flex panel is made of two layers of elastic, and allows the belt to expand slightly when bending or kneeling. It also provides some expansion without having to adjust the length of the belt, adding comfort. A hypalon oval sewn on the inside of the elastic panel helps keep the belt from sliding or shifting around the waist. The use of hypalon for the pull tab and metal loop end of the belt ensures easy threading of the loose end and less wear on the belt due to the hook Velcro snagging on webbing.

A neat feature of the 1.5" and 2" Flex Inner belts is the storage compartments. The belts will have four 5" long compartments, with two smaller ones depending on the size of the belt that is ordered. On the 1.5" belt, the compartments are 1.2" tall (the seam takes up some space along the edges of the belt), and the 2" belts have compartments that are 1.75" tall. Any kind of flat items can be stored in the compartments within reason, as long as they're not too thick or inflexible. SD cards, cash, gold or silver coins, keys, etc can be secretly worn on the body.

Notes/observations - The Flex Inner belt is similar in design to their Adam Belt, which is a simple, low profile trouser belt with no buckle, but an overlapping Velcro closure. The Flex Inner belt is like an Adam Belt 'plus', adding more features like the complete exterior being covered in loop Velcro. I don't typically use an inner/outer belt system as my gun belts don't always sit exactly where my pant belt ends up. It depends on the rise of the pant. But, many people do use inner/outer belt systems so the Flex Inner belt is compatible with any outer belt that is lined with hook Velcro.

The metal loop has less bulk than a plastic loop or buckle, so the Flex Inner belt is comfortable under an outer belt. When adjusting the belt and donning it, I don't tuck the loose end into the belt loop as it's a bit of a pain to thread through and pull back out as the velcro engages. I just did it for the picture above. I couldn't tell whether the hypalon oval at the back is effective in preventing the belt from sliding, but sticking the loose end over the first belt loop captures it, and by default, prevents undue movement.

To test out the compartments, I put folded bills in them and single keys, and once on the pant I forgot that they were there. Note that the 2"-wide belt will accommodate larger items obviously. For the 1.5" belt, I had to fold bills over in thirds, while for the 2" belt, I only had to fold them over in half (width wise), and then once again length-wise. You can stick a velcro patch on the 2" wide belt to serve as a 'buckle', or to advertise your company/brand/whatever. If you really want to annoy people, you could also cover the whole belt in patches. Why? Because 'tactical'. Might be a good belt to walk around SHOT show with and to collect patches on. All joking aside, it's a well-made, simple, inner belt with some added functionality - good stuff!