​​​​​​All chainsaws will arrive with a full bar and chain oil tank that will last approximately 30 minutes to 1 hour's worth of use.  This is a specialized oil that lubricates the chain during operation.  It's strongly recommended to have additional bar and chain oil on hand (and to check the oil reservoir frequently) to avoid damage to the equipment.  
 
Genuine OEM Stihl Part
Contains Highly Refined Oils For Maximum Lubrication
Is Designed For High Speed, Heavy Duty Cutting
Contains Concentrated Tackiness Additive To Help Oil Stay On Saw Chain At High Cutting Speeds
Extends The Life Of Chain Saw Bars And Saw Chains