There are actually 3 types of thumb straights that I know about and used for the better part of 18 years (just stopped using them last year). The first kind was red and pretty slick in texture. The second was grey, rubbery in texture and had little ridges on the section your thumb would lay against. The third, and these are the Ebonites, are black and also kind of tacky in texture.

They simply fit snugly inside the existing thumb hole (make sure you order the right size). They are prone to shifting upwards slightly so I use to position them and then add a dab of super glue to keep them solidly in place.

When I made the change to switch grips the thumb straights made it difficult to change out the grips (but not impossib;e). I actually stopped using them when I went into a slump and was desperate. It wasn't easy because you really do get use to the feeling the thumb straights give which is equivalent to adding reverse pitch.

If you'd like one free of charge I'd be happy to send you one. Mine are all "B" size and fit in a 61/64's hole (and I think as small as a 59/64ths).

Edited on 9/16/2006 9:28 PM

Edited on 9/16/2006 9:28 PM