Everyones different, I cant gurantee anything.
IMHO a routine with at least 30 minutes going onto a max of 1 hour and 30 minutes is enough. With consistancy it'll work.....but also the key to erect gains is working the unit when at MAXIMUM erection and constriction make that happen. Push the penis past its MAX capacity reguler and it grows better than it would in manuel methods. Its all in time [Dont do too much i.e 30-90 minutes], consistancy [Keep reguler and you'll see gains cement and become permanent] and finally volume [Get the penis as erect as you can for anything aimed at erect size....push the size further, like you have putty in your hands 'penis', and mold it into something bigger i.e doing AHS and it becomes fatter , or stretches and it becomes longer. Much better than manuel methods because your working with ALOT of blood and thats what the penis uses in order to make the size changes].