that is a german machine head that is designed to allow those of you who are determined to stay with 4 string basses reach the low notes that us 5 string bassists get to with the low B ....
it is a schaller D turner ... you flip a switch and your low E is low D ... it works better on 34" scale basses ...
Actually, I believe that is a Hipshot Bass Extender with a Gotoh GB-7 tuner. Hipshot makes a variety of these with different brands and types of tuners to match the existing tuners on your bass. Unfortunately this one doesn't quite match!!!
I was just looking at these on the Hipshot website. It's not the model made for Ric's. The guy is probably cheap and didn't want to pay for the correct one, so he drilled holes for the one he had.