Do you want to be sure of having a safe helmet? Then Back on Track is a great choice! They manufacture riding helmets of the highest safety standard, and in 2018 their EQ3 Lynx won Folksam's helmet test as the safest helmet.
Back on Track's helmets have the MIPS safety system, which protects the head against rotational movements and can reduce the risk of, for example, concussion or cerebral haemorrhage in case you fall off you horse. The helmets have good ventilation and a smart screw function at the back, which means you can easily adjust the size.