This is a Mamiya RB or RZ Large Focusing Knob.  Using this will allow you to focus faster.  Just pop it on over your existing focusing knob. 

This knob is in excellent condition.

 

WE SHIP IN 1 BUSINESS DAY as well we package professionally and will combine to save on shipping costs. We are also interested in BUYING your photographic equipment as well. We are Camera Exchange in Waterford Michigan.

 

4182360