I agree with @Rahila , they’re not recommended in advice you to do some research . A lot of accidents happen.
I don't personally have them as I don't feel I need them, but if you're looking at them, I'd go for the breathable mess ones. Made from the same material you see in the Next-To-Me cots when the sides are up. https://amzn.eu/d/72vBt7n
They aren't safe, even the ones that say the are breathable. They come undone or babies pull them the get tangled and strangled. Instead of looking at reviews, look at news reports
I use the breathable ones and never had a problem 😌
I use them and have never had an issue. Stops them from banging their heads and dummies flying over. BreathableBaby Breathable Mesh Liner For Cot Beds — Covers 2 Sides — Classic — 3 mm — Twinkle Grey — 2 Panels — Non-Padded Single Layer — Safer Than a Crib Bumper — UK/EU Safety Tested https://amzn.eu/d/8oKUgzh
Thanks ladies
They are not recommended as they are unsafe for babies, I remember the health visitor specifically asking me if I had them or not just to check. There are NHS guidelines on safe sleep too x