A catalyst subassembly for a device for purifying exhaust gases from an internal combustion engine, in particular a diesel engine, includes an SCRF catalyst and an SCR catalyst upstream of the SCRF catalyst. The two catalysts are arranged in a common catalyst housing. The catalyst housing, the SCRF catalyst and the SCR catalyst can be selected from a modular system for different variants of the internal combustion engine.

A mat material having a generally rectangular shape in a plan view, the mat material including inorganic fibers, wherein the mat material includes a first main surface and a second main surface opposite to each other in a thickness direction, a first end surface and a second end surface opposite to each other in a longitudinal direction that is a winding direction, and a first side surface and a second side surface opposite to each other in a width direction perpendicular to the thickness direction and the longitudinal direction, the mat material includes, on the first end surface, a protrusion designed to protrude toward the second end surface during winding of the mat material, and non-protruding portions provided at both sides of the protrusion in the width direction and designed not to protrude toward the second end surface during winding of the mat material, the mat material includes, on the second end surface, a recess designed to fit the shape of the protrusion on the first end surface during winding of the mat material, and non-recessed portions provided at both sides of the recess in the width direction and designed to fit the shapes of the non-protruding portions on the first end surface during winding of the mat material, and a ratio [D/C] of a length [D] of the non-recessed portion in the width direction to a length [C] of the non-recessed portion in the longitudinal direction is 1.0 or more.

A device for aftertreatment of exhaust gases from an engine, with a honeycomb body through which a flow passes along a main flow direction, a ceramic mat, and a first casing that receives the honeycomb body. The ceramic mat is arranged between the honeycomb body and the casing and surrounds the honeycomb body as a ring in peripheral direction. The ceramic mat is configured such that the cavity formed between the honeycomb body and the first casing is filled by the ceramic mat. A method for manufacturing the device, wherein the honeycomb body is received in a second casing and the honeycomb body received in the second casing is surrounded by the ceramic mat as a ring in the peripheral direction. The second casing has, at the end region facing the gas inlet side, a portion having a structure different than the remaining structure of the second casing.