[Reliable Quality]: This gear is made of the same brass material as the old parts. The brass gear has high strength, wear resistance is its biggest advantage, and it has the characteristics of resistance and aging resistance. And the hardness is relatively soft, so it is not easy to damage the internal parts of the engine. [Replace Part Number]: 420935736, 290935735, 420935735. [Compatible with]: for 580 All /587 All / 650 All / 657 All / 717 All / 720 All / 787 All / 800 All. [Function]: When shaft gear is severely worn, it needs to be replaced. This gear is manufactured according to the standard size of the old gear and is a perfect substitute for the old gear. [Installation]: The replacement of this gear is very simple, first find the position of the rotary valve drive shaft on the engine, then pull out the rotary valve drive shaft to replace it. One-person operation saves time and effort. Name:Rotary Valve Gear Color:As Shown Material:Brass Package Contents: 1 * Rotary Valve Gear Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.