These things are pretty self explanatory. Like the name states, they’re tires to be used on stationary indoor bike trainers. They’re made by CycleOps, one of the most reputable brands in the business, but you can of course use them with any trainer regardless of brand name.
These tires are way more quite and offer way more grip on the trainer than standard tires, and they won’t wear out nearly as quickly. They’re $51 each (and of course you need just one, for the rear wheel) and will pay for themselves in a single season by saving your outdoor tire for the pavement.
You can use them on virtually any 700c road wheel. We just have the black ones in at the moment, though there’s no difference between the two colours other than, well, colour.