Schwalbe SV 40mm Tube Item 4 (16"/18") 16-18 × 1.1–1.45

Schwalbe Standard inner tube no. 4. for bicycle tires in sizes 16" and 18" inch (ETRTO 28/37-340/355). Retains air for an above-average length of time. Thanks to the best material quality and uniform wall thickness. Maximum reliability that has proven itself millions of times over.