As a substitute for weights if you are traveling, these bands definitely do the trick. You can do some pretty intense exercises. They seem pretty strong as well, so you do not have worry about them breaking as long as they are used properly. Performance For a workout where you cannot find weights, these bands can deliver results. Ease of Use They are very easy to use. Durability They seem quite strong and are not likely to break. Design They are very lightweight. You can take with you literally anywhere.