I struggle with written directions - I lose track of what they are talking about. I've had this needle pusher for years (from BSK) and never used it before. Last weekend I decided to knit a sideways-knitted skirt - based on one from the Mary Weaver book. It has wedges of holding position between straight sections. The wedges were 14 needles in hold x 4 then 11 needles in hold until only 16 left in work, and then back out again. I'd already done one wedge by counting - which took ages - and had walked away because I couldn't face another 11 wedges. Then I remembered I had this tool - and it works really well. It could also be used for the chunky gauge (9mm) if you double the number.
It's basically a simple plastic ruler with a sliding part that sticks out and allows you to easily select the required number of needles.
I'm not saying the skirt was great - I got sloppy about wrapping needles so there are some holes, and it needs grafting and a hem treatment - but it sure went a lot faster!
Pushing needles into hold
Returning needles to Upper Working Position (UWP)