i was looking at buying these adjustable dumbbells a few year ago. i think you can make them go up to around 75kg per hand....saves having tons of different size dumbbells hanging around. but they are pretty pricey and even more pricey to get them in the UK. so i didn't bother inn the end.
https://www.ironmaster.com/products/quick-lock-adjustable-dumbbells-75/
