As steel gutters are not symmetrical, gutter angles are either internal or external. The product image clarifies the difference but essentially if you are stood in front of an external corner, the corner goes away from you out of sight. External corners are usually used on all 90 changes of direction except at the foot of a valley, where you would use an internal corner. An internal angle is one that comes towards you as you stand in front of it.Unlike most steel gutter systems, Galeco 90 Degree steel gutter angles come with a clamp and seal, reducing the need for additional unions and allowing for quick and easy fit.Angles should be supported by installing a fascia bracket with 150mm of the corner.