This is an adjustable rear axle for a Yamaha Raptor YFM700. This fits various years. Yours has one course spline like the one pictured in the URL supplied which to my knowledge was only used on the YFM700. The maker of yours is unknown. There are many aftermarket axles available from numerous manufacturers that will interchange on the various Yamaha ATV's (Raptor, Blaster and Banshee) using the same axle and assembling the spacers in different order or from moving them from side to side depending on the style of the bearing carrier. The one pictured in the URL is made by Niche Industries and is the closest one I could find to yours.

It's an "adjustable width" rear axle for a 1986-89 Honda TRX 250 atv. The end splines are longer and there are spacers that can be used to vary the wheel spacing.

References:

https://www.ebay.com/itm/1986-1989-TRX250R-TRX-ATC-250R-ATC250R-REAR-ADJUSTAB...

https://www.ebay.com/itm/Dura-Blue-3-Piece-Posi-Lock-Nut-HONDA-TRX-250X-FOURT...

Reason:
Thank you for the opinion, but I am having trouble verifying the fitment, the Posi Lock Nut you refer to is more rounded, and the one I have has more square edges, also on the shaft the grooves are different from mine

This is an adjustable rear axle for a Yamaha Raptor YFM700. This fits various years. Yours has one course spline like the one pictured in the URL supplied which to my knowledge was only used on the YFM700. The maker of yours is unknown. There are many aftermarket axles available from numerous manufacturers that will interchange on the various Yamaha ATV's (Raptor, Blaster and Banshee) using the same axle and assembling the spacers in different order or from moving them from side to side depending on the style of the bearing carrier. The one pictured in the URL is made by Niche Industries and is the closest one I could find to yours.

References:

https://www.ebay.com/itm/Adjustable-Rear-Solid-Axle-2006-2017-Yamaha-Raptor-7...