Attachment for a heat exchanger

A heat exchanger comprising

• a first fluid channel for a heat exchange fluid, having a channel wall formed by a heat exchange plate, an attachment, including
• an attachment base plate extending within a base plane, having a bottom side and a top side between which a thickness of the attachment base plate extends,
• a plurality of contact portions extending away from the top side independently from each other,
• wherein the attachment base plate is of rectangular, elongated outline extending along an attachment longitudinal axis and an attachment lateral axis, the extension along the attachment longitudinal axis being predominant,
• wherein at least one contact portion has a different longitudinal length than another contact portion, the longitudinal length being measured along the attachment longitudinal axis
• wherein the attachment is attached to the channel wall by the bottom side.