This is the Idler Pulley Plate. It can be used with both V-Slot.
The idea behind this plate is to give you a mountable yet movable plate for your Smooth Idler Pulley. This works great as it allows you to easily tension your belt.
There are a lot of possible mounting configurations for this plate.
6063-T6 Aluminum
Black Anodized Finish
3mm~ (1/8") Thick