The present invention relates to a spool 4 for a spinning reel being mountable on a spool shaft 15. The spool 4 includes a spool body 42 that rotates with respect to the spool shaft 15. The spool 4 also includes a drag mechanism 43 between the spool body 42 and the spool shaft 15 to apply a braking force against a rotation of the spool body 42. The spool 4 further includes a radiator 44 in the spool body 42 and in contact with the drag mechanism 43. The radiator 44 rotates with respect to one of the spool body 42 or the spool shaft 15. The radiator 44 does not rotate with respect to the other one of the spool body 42 or the spool shaft 15. The invention further relates to a spinning reel comprising such a spool 4.
