For those of you that have been waiting for a solution on your pro shaft drive planters, Ag Leader now has you covered.  Their innovative new style shutoff makes installation very simple, and provides reliable and repeatable results in the field. 

My experience with these in the field has been very good.  They have been tested with several different types of seed discs, and all have worked well.
The SureVac row shutoffs will be on display this week at the Iowa Power Farming show, or feel free to contact me with any questions you may have about them