Those are great. You can get by without, I found you needed to set just a bit off before tightening the nut, which would put it back in sync. It's a bit of trial and error to get the right amount "off"
I made my own balancer last year with some clear tubing, a drywall T, zip ties and a ladder. I used the acid bottle I got with my battery as an aux tank which rested atop the ladder.