There are perforations under the midfoot and forefoot. This helps reduce weight and improve breathability of your insoles, which is especially important if you tend to sweat a lot.
The Superfeet Carbons fit in a wide range of tight-fitting sports shoes, like cleats and running shoes. They're lightweight and breathable, and provide support, balance and comfort.
The heel caps and arch support are shallower than any other Superfeet insole, but the basic construction is the same. This allows the Carbon insoles to fit in a wider variety of shoes, and can even fit some dress shoes (if they have removable insoles). The Carbon insoles stabilize and support your feet by keeping your heel in position, and letting the heel caps absorb part of the shock as you're running. This reduces stress on your feet, ankles and knees, so you'll be more comfortable instantly (if you get the right size).
Superfeet insoles can not be machine-washed. You need to hand-wash them with soap and water, and allow them to air-dry. If you do so, they will last for up to 12 months or 500 miles, whichever comes first. Some users have reported that they still have the same pair after 2 years and approx. 2000 miles, so it's likely they'll last a long time.
The perforations improve ventilation, and the closed-cell foam has antimicrobial treatment, which discourages bacterial growth and helps reduce odor. The closed-cell foam also means that there are no pores in which bacteria could grow.
Superfeet recommend wearing their insoles a few hours at a time for the first week, so your feet get a chance to get used to them. However, many users have stated that they instantly felt a positive difference, and didn't need aay adjusting time. Still, you should be careful to pick the correct size and arch height for your feet, and allow some time before returning them.
Spenco Comfort insoles are a great way to make your dress or athletic shoes more comfortable if you're not looking to cure any ankle or knee pain. They're made of neoprene foam, which provides some shock absorption and a lot of cushioning throughout the whole foot. There's an antibacterial surface, which helps your shoes smell fresh. They cost under $10, which is about five times cheaper than more orthotic, support-oriented insoles.
These Spenco insoles have a very low profile, which makes them ideal for both dress and athletic shoes or other tight-fitting shoes. They can fit over the original sock liner of your shoes without a problem, so you don't have to tear the original sock liner out as you would with more support-oriented insoles. They can be trimmed to fit any shoe perfectly.
The Spenco Comfort insoles are uniformly thin and they don't change the shape of what's underneath them. Custom orthotics tend to be hard (for good reason), so if you want to make them more comfortable, the Spenco insoles might be a good option.
Because they are so thin, these insoles might wear out faster than the harder, more supportive insoles. Some users have said they last for a few months, but some have mentioned a whole year in durability. It probably depends on how often you use these, but don't expect them to last a lifetime. These Spenco insoles are very reasonably priced, so replacing them wouldn't be a major setback for most people.