How to resize Studio widgets

I have been trying to implement Roblox’s Studio Widgets from GitHub, and they are working well.
The only problem is that I cannot figure out how to set their size or layout.
Here is what I currently have:
StudioSlider

Notice that the slider is sticking off the edge and there is way too much space around the word “Diameter”.
This is my current code:

diamSlider = SliderClass.new(
	"suffix", "Diameter", 50,  2
)
diamSlider:GetFrame().Parent = newWidget
diamSlider:GetFrame().Size = UDim2.new(0, 20, 0, 25) -- Doesn't seen to do anything
diamSlider:GetFrame().Position = UDim2.new(0, 10, 0, currentY)

How can I change the width of the LabeledSlider element? Is it possible to create a slider without a label?