These hollow bronzes of feet are used in the Alankar of deities taken out in procession. The usage is possibly best explained with reference to the two pictures below. The vigraha is Amman (translates to Goddess and here it refers to Parvati) and the occasion is ten-day Karthigai Deepam festival in Tiruvannamalai. The photos are from the first two days of the festival and it is from the site https://www.thiruvannamalai.in/. 
As you can see the first day Amman is seated with her right leg pendant and whereas on the second day she is sitting in Ardhapadmasana. The vigraha is the same in both the pictures. The poses of Amman are created with ‘made up’ legs.  Hollow bronze feet, similar to the subject of this blog, are used for the visible portion of her legs.

In this example, the big toe and the second toe are adorned with toe-rings, called Metti. Wearing Metti is normally a sign of married women, though it is recorded that in earlier days men also wore toe-rings. The anklets are quite robust and look like dancer’s anklets.

Kavacha normally refers to body armour or body cover. In this case use of the word, Kavacha may not be right. Hence the tentativeness in the title.

This bronze is from Tamil Nadu and it is about 17 cm long and 9.5 cm high. This bronze may date to the nineteenth century.  It is unusual to see a well preserved matched pair of feet.

The ratio of feet length to the height of a person is about 1:6. That would make the height of the idol about 1 meter (39 inches). Quite a substantial bronze.