The locking ring is used in combination with the ground level ring and is usually applied around sports fields. The ground level ring prevents weeds from growing directly along the post, while the locking ring fixes the surface ring and prevents the post from subsiding. Locking rings are available in sizes 60 and 90 millimetres and in different finishes: aluminium, aluminium RAL 9005 black and aluminium RAL 6009 green.