Grippa do them they give you the option over the single ones,some microbore hose seems thinner in diameter these days.
Some single crimp ones when you put them over the microbore you can almost get your little finger under the gap the rings are so big,ask for the smaller diameter O rings double eared that go with the hose you have,they do slightly bigger ones as well just ask for the smaller ones you’ll get a much tighter fit,always a good idea at the end of the day to drain what’s in the hose if you have a back to tank option like me coz I’ve got a heater it automatically does this for me anyway puts what’s in the hose back to tank.