So I have a Shimano Saros 3000F and the rubber on the knob is warn down almost completely to the metal. I know I could just buy the replacement part from shimano but they are not cheap and I am not a huge fan of the design. I was curious if there is an option to get an aftermarket knob for this reel. I looked at hawgtech and like the winn grip but wasnt sure if they would fit on this reel. Any suggestions on brands or what types of knobs fit this reel is much appreciated.

First check to see if the knob is removable. Some are riveted on and if that's the case you'll have to buy the entire handle assembly. If it's held on by a screw 'I believe the saros is removable' then it's a standard size Shimano knob post. If so then you can buy a single knob from whatever company you like. 

Zpi  

basszone

Livre

Yumeya

Avail

The knob is removable and can be ordered from Shimano without ordering the entire handle assembly.  Any aftermarket 'A' style knob will fit.  I think a Hawgtech Winn Grip would be perfect.

Footnote:  Just found out Winn Grips only fit Hawgtech's baitcasting handles.