They should fit in a way that allows space for a hand to pass by. It is also important that they must sit correctly in the position. A proper fit bit is the one that sits in the corner of the mouth and offers one crease in the lips. Moreover, the noseband should fit 1 to 2 centimetres below the cheekbone, except if it is a grackle that fits differently. However, if you are using a drop noseband, make sure it fits carefully to interfere with the horse’s airways.