If your bike has a Quick Release (QR) rear wheel, that is an axle which has a lever which folds out to, it'll fit onto a Turbo Trainer. If your bike doesn't have one, you'd need to replace your rear axle with a QR skewer, though this usually involves replacing the rear wheel as well. If the Turbo Trainer your looking at has a direct drive, meaning it has a cassette already on the base, then you won't need to worry about this. Some models don't come with a cassette included, so you may need to buy this separately. When buying a Turbo Trainer, please consider extras you may need such as a trainer tyre and a front wheel block.