They are basically in the category of a three-leaf ring, a ring with three leaves confined in it, which have been excavated from Sekiganri Kofun Tumulus in Rakuro (an ancient county existed in the northern Korean Peninsula).
基本的には楽浪の石巌里（せきがんり）の古墳で出土しているような環の中に三葉形を入れた三葉環である。