The invention relates to a tyre-type device for equipping a vehicle, with an improved flattening of the tread thereof compared to a standard tyre. The tyre-type device (1) comprises a radially outer revolution structure (2) which comes into contact with the ground, a radially inner revolution structure (3) which is coaxial to the radially outer revolution structure and used to provide the connection to an assembly means (4), an inner annular space (5) radially defined by the two revolution structures, and a carrier structure (6) at last partially connecting the two revolution structures and consisting of a plurality of carrier elements (7), pairwise independent, subjected to buckling under compression in the area of contact (A) with the ground. According to the invention, the smallest characteristic dimension E of the section S of any carrier element (7) is at the most equal to 0.02 times the average radial height H of the inner annular space (5), the surface density D of the carrier elements (7) per surface unit of the radially outer revolution structure, expressed in 1/m
2 , is at least equal to Z/(A*∑Fr/n), where Z is the nominal radial load, expressed in N, A is the ground contact surface, expressed in m
2 , and ∑Fr/n is the breaking strength in average traction of the n carrier elements subjected to buckling under compression, expressed in N, and the tyre-type device comprises two sidewalls (8) which are not connected to the carrier structure (6) and close the inner annular space (5), forming a closing cavity that can be pressurised.