Specification Brand : TMP1105 BulletPoint1 : 9T-1.0mm gear Size specification: (with slight error) BulletPoint2 : Number of teeth: 9 BulletPoint3 : Inner diameter: 1mm BulletPoint4 : Outer diameter: 3mm; Height: 4mm BulletPoint5 : Note: The delivery only has gears, not including the motor. Color : 9 Teeth ExternallyAssignedProductIdentifier : 8306070440114 ItemName : TMP1105 Small Hollow Cup Motor 9T Gears 1mm Hole for 720/820/716 for Coreless Motor Aircraft Model Accessories (Hole Diameter : 1mm, Number of Teeth : 9 Teeth) ItemPackageDimensions_Height : 1 centimeters ItemPackageDimensions_Length : 100 centimeters ItemPackageDimensions_Width : 1 centimeters ItemPackageQuantity : 1 ItemTypeKeyword : rack-and-pinion-gears Manufacturer : 唐铭鲆544162-US Material : Plastic NumberOfItems : 1 PartNumber : 唐铭鲆544162-US ProductDescription : Small module gear is used for toy accessories, for mini cars, for remote control aircraft etc. How to calculate the calculation of gear? (for reference only) Gear module M = outer diameter ÷(number of teeth +2) Outside diameter = Gear module ×(number of teeth +2) ProductSiteLaunchDate : 2021-09-10T05:30:40.515Z Size : 1mm UnitCount : 1 UnspscCode : 52140000