Replacement Bulbs: These bulbs are a replacement for OTC number 3642 and come in a pack of 10. Compatible Model: The bulbs are designed to fit OTC 3642 models and replace worn out or broken bulbs. Convenient Packaging: The 10 pack packaging allows you to keep extra bulbs on hand for future use and replacement. High Quality: These bulbs are made to OTC specifications for optimal performance and longevity.