What kind of oil do you use in a blower?

Could you please elaborate on the type of oil that is typically used in a blower? Is there a specific type or brand that is recommended for optimal performance and longevity of the equipment? Are there any precautions or guidelines that should be followed when selecting and applying the oil to ensure the SAFE and efficient operation of the blower? Additionally, how often should the oil be changed, and what are the signs that indicate it's time for a change? Thank you for your insights.