A pair of handforged steel stirrups

The arches are bent - possibly as a safety feature or to help keep one's heels down. They have integral suspension loops.
The hollow oval treads have diagonal grooves to help grip.
The undersides of the stirrups are stamped with arrow ordnance marks, "Steel 1915" and "Heney", there are other stamps which I cannot read

Dimensions : Width 5¼" (13.2cm), height 5½" (14cm), depth of tread 2¼" (6cm)
Weight : 733g (1lb 10oz)