What is this?

[fraze11]

Is this for the front?

http://www.ebay.com/itm/GS500E-GS500F-GS500-Carbon-Fibre-Fenda-Extenda-Fender-/270938083625?pt=UK_Motorcycle_Parts&hash=item3f152b1129

[Tombstones81]

yep.
that lip in the front  goes beneath the back side of the front fender.

[adidasguy]

Ignore the circle, but you can see one here on the back of the front fender. They were stock from 1989 to somewhere in the late 90's. They help keep road crap off of your feet and the engine.

[twinrat]

well worth it to keep crap off .I only have one recomendation and that is to put black RTV in the joint ,otherwise you get a mess down the extender from the joint in wet weather .

[adidasguy]

well worth it to keep crap off .I only have one recomendation and that is to put black RTV in the joint ,otherwise you get a mess down the extender from the joint in wet weather .

Good suggestion. Though my OEM ones fit rasther snug and I have not experienced that yet. Then maybe we have so much rain the "Seattle Bike Wash" rinses it all off. 

[noworries]

Blimey, that company must have cornered the entire world market in motorcycle fender extenders.

[adidasguy]

I only have OEM fenda-extenda's
Maybe I should get some of those?

I have seen others. and OEM are still available.