These are silver coloured, probably nickel plated spurs with steel inserts which would fit into "boxes" in the heel of the boot.
Both of the inserts have surface rust, but it is just possible to see that they are stamped with Maxwell's Dover Street address.
The necks are straight and faintly stamped "Maxwell".
The rowels are decorated with a thistles.
They have a few surface scratches and one has an area of worn plating about 1cm in diameter on one arm..

Internal width 7cm (approx 2¾"), neck 6.5cm (2½"), rowel 2.5cm (1")
Weight : 195g (6⅞oz)

Ref : spur521f