Standard 30x30mm extrusion profile. They exist with a 8 or 6mm groove.
This type of extrusion profile is compatible with TNuts made for each groove size.
Very robust, they are used on Scalar M, Scalar L, Scalar XL and Scalar XL Premium 3D printers
These are 20x20mm .They exist with 5mm or 6mm grooves.
They are also compatible with a big range of accessories.
They are also lighter and cheaper than the 3030 extrusion profiles.
2020 VSlot profiles:
They are also 20x20mm. They have V Shaped grooves.
They are ideal if you want to use them as sliders with Special V shaped Wheels
They are used on Scalar S, Scalar L, and Scalar XL premium 3D printers