Do you have the part numbers? I'm not sure what you are referring to.
If you mean the circle cutting attachment, then it's the same for both the 400 and 420, but it does come with or without the ADT-PS 420 base; perhaps that's where you're seeing a price difference?
There's no difference.
The KS-PS 400 is named after the older model PS 400 which was discontinued because it was a faulty machine.
They probably renamed it to KS-PS 420 after the new model jigsaw PS 420.
Do you have the part numbers? I'm not sure what you are referring to.
If you mean the circle cutting attachment, then it's the same for both the 400 and 420, but it does come with or without the ADT-PS 420 base; perhaps that's where you're seeing a price difference?
There's no difference.
The KS-PS 400 is named after the older model PS 400 which was discontinued because it was a faulty machine.
They probably renamed it to KS-PS 420 after the new model jigsaw PS 420.