Originally Posted by rmdhawaii

Go to the Web page below and choose the MTX-4. It will list your options.

http://www.bocabearings.com/main1.as...earchkit&cat=1

I would choose the Ceramic Lightning Ultra Seal Bearing Kit #40-110C-YU for my MTX-4, as I am using these on my RRR. Have not tried the yellow seals. The differences between the seal types can be found here (well, sort of):

http://www.bocabearings.com/main1.aspx?p=docs&id=5

YBSLOW - What are you using??