'Grand Slam. The Si-18 International is an classic silhouette built for tennis. Features such as the signature D-R-Cinch lacing system and heel stability counter were designed for you to give it your all on the court. The mid-top sneaker's full leather upper is complemented by vintage branding elements, including an embroidered tongue tag that pays homage to the four host countries of tennis' most prestigious tournaments. Off-court style gets a polished, sport-rooted update with a silhouette inspired by classic tennis design. The K-Swiss SI-18 International Heritage pairs premium materials with standout archival details, bringing a clean look, supportive feel, and vintage attitude to everyday wear. Signature elements like the D-R-Cinch lacing system, heel stability counter, and embroidered tongue tag nod to the legacy of one of K-Swiss' most iconic court models. Styling & VersatilityWith its heritage tennis lines, crisp paneling, and retro branding, this pair is easy to dress up with elevated casual looks or keep classic with denim, leggings, and sporty separates. It brings just the right mix of vintage court energy and everyday versatility."