Most sleeved tubes have little resistance. These are perfect for my needs. I bought the #1, 3 and 5 for different training, and the resistance difference, #5 being the strongest, has helped me put serious focus where I want. I train 6 days a week, repeating 3 different workouts 2 times a week, working different muscle groups. I only use free weights 2 times a week now because these tubes are so versatile. I am 67 and as a retired construction electrician am in better shape now than when working with the tools.
I use a ton of resistance bands with my clients. Finding a good quality band, especially with the protective sheathing, can be difficult. There isn't much else to say but that these are great bands and I'll be buying more of them.