坦桑尼亚采购需求：共轨部件、柴油发动机部件、备件

I am reaching out to inquire about the availability and pricing for a specific type of O-ring. We are interested in various sizes and materials that meet industry standards. Please provide details on the options you have, including any bulk discounts, lead times, and minimum order quantities. Additionally, it would be great to know if you offer any samples for testing purposes before we make a larger commitment. We're looking for a reliable supplier for future projects, so any information about your quality assurance processes and certifications would be appreciated as well. Looking forward to your prompt response.