Simple and practical design The unique opening allows easy insertion and the depth matches the rim hole for Presta valve seating. Durable and protective Made from polymer plastic with good shock absorption to reduce stress on the rim hole and valve. Standard size and versatile look Size: 9 x 8.5 x 6.1 mm. One size fits most rims. Classic black/red finish complements tires of different colors. Value and convenience 10 pieces per pack. Ready for multiple bikes or workshop use, reducing the need for frequent replacements. Compatibility and performance Specifically designed to enable a Presta valve to fit into Schrader rim holes, protecting the rim and improving installation reliability. Use scenarios Road bikes or mountain bikes with Schrader rims running Presta valves: quick and safe conversion during tire changes. Bike shops or maintenance crews: keep a spare set on hand for customer wheel sets and onsite repairs. Travel or race day: carry as a compact contingency for adapting valve types across different wheels. Why you need it Protects rim hole integrity, minimizes valve stress, and speeds up tire changes without special tools.