The scawbrig can be bought as a whole bridle or again just the noseband part. Its made of rings at the sides of the noseband which a strap goes through from a rein, under the chin and out through the other ring to the other rein. These mostly offer chin and nose pressure.
They dont seem to be that popular but I have seen a gelding go really well in one of these so its always an option to try.
Ive put a link below as a photo as I dont have one of my own just now.
https://www.redpostequestrian.co.uk/dpt/pgr/libbys-scawbrig-bitless-bridle--black__42153