Double-Ended Perfect Fill Lip Brush

I just received a replacement for the original brush purchased online and unfortunately this second brush came with the same fault - the cap does not stay on. Also, now that I have actually tried using it, I realise that the bristles at the wider slanted end are way too soft. They absorb a lot of the lipstick, but do not transfer it onto the lips to the extent you would expect. The other thinner end seems to be fine. Overall, I am not happy with this purchase and wish I opted for a refund instead of the replacement.

Like the duality - it's amazing how hard it is to find something like this on the market. A nitpick is that it's a bit hard to clean if you forget to wipe the ends before retracting / capping them - the insides of the brush / cap get dirty with lip product. It's also hard to find tutorials on how to properly use the brush.