4.5 mm standard gaugeneedle selectortool 2x1 2x2 - The name says it all! This is an unusual configuration for a needle selector tool. 2x1 and 2x2. Use the needle selector tool to select 2 needles leaving 1 behind in non-working position. In other words 2 up 1 down. Set the ribber at half pitch. Use the same tool to push up 2 needles opposite the 1 needle down on the main bed for make "industrial" rib.
The other side of the tool selects 2 needles up and 2 needles down. This would be for 2:2 ribbing.