Premier Designs Black Leather Like Necklace

Premier Designs slightly thicker black leather like necklace w/extender. In good used condition. I’m unsure if this is actual leather. Simple necklace w/silver tone extender & lobster clasp. Has a slight ‘warp’ - may straighten out with heat? Can be adjusted from approximately 15 1/2 in to 18 1/2 in. 0102 J3