So once you start unscrewing the lid it's tight but manageable. However, when you get to the middle, you will feel VERY, VERY comfortable. With some effort, I screwed the caps all the way in. However, unscrewing it has become a grueling task. To unscrew them, you need to muster a lot of muscle. And I'm actually quite fit/athletic. One lid was so tight I had to use pliers to unscrew it. I highly doubt that neither my elderly father nor my girlfriend would have been able to unscrew these caps by hand. If I had to do it again, I wouldn't buy them again. I would not recommend these at all. Not that it matters, but for the Toyota RAV4.