Total legth = 22.5cm or 7 inches for the key alone and another 2 inches for the attached rings! This type of key is sometimes called a latch lifter.
This large beautiful key is made of Iron and complete with a line and cross decoration. Because it's made of iron and so large and so well preserved it is very rare.
It has two prongs on the bit end and also a ring is attached to the end of the handle. Notice also it is connected to two chain type links. Very unusual!