Protective ring for a horology movement and horology movement including said protective ring

A horology movement comprising a cage formed by a plate onto which a bridge assembly is fixed, said plate forming a radial shoulder with respect to the bridge assembly by a lower face, the horology movement also including an oscillating mass which is rotatable with respect to said cage and extending radially beyond the bridge assembly, wherein said horology movement includes a ring made from a material having ferromagnetic properties and comprising a tubular body extending between a first and a second axial end, said ring being configured so as to encircle the bridge assembly and to extend axially towards the oscillating mass, and being adapted to form, by the first axial end, a stop limiting the angular displacement, about a radial axis, of the oscillating mass, said ring including fixing members extending from its second axial end axial, engaged in housings formed in the lower face so as to fix the ring with said horology movement.