I used them since they first came out. I don't see the point in covering the glass twice, when you can do it in one single pass.
They will fit the old unger b,o,b, when in the single pass position.
The Wagtail is a far better tool though, half the weight and uses very little water.
The Wagtail uses a pad instead of an applicator.
With the Wagtail, I actually put a couple of cupfulls of solution in my B,O,B.
One bucket full can last a couple of days. I just rinse the pad under a tap occasionally. When you do the insides there is virtually no mess at all, they use that little water. On really dirty, or salt encrusted glass, you just go over it twice without lifting the blade off. The wagtail beats every other tool in speed trials.
Every shiner that have tried my Wagtail, wants one.
I have no connection with Wagtail, They are an Ausralian outfit. I am trying my best to get UK suppliers to take them seriously, It can be expensive to import them.
IF YOU CAN GET HOLD OF A WAGTAIL, GET ONE. YOU WILL NEVER LOOK BACK.
dai