b0872c8c_n_for_JQuery___BttrLazyLoading__description
[Name] threshold [type] integer [default] 0 [description] 
By default images are loaded when they appear on the screen. If you want images to load earlier use threshold parameter. For instance setting a threshold to 200 end up loading the image 200 pixels before it appears on viewport.
Responsive Lazy Loading plugin for JQuery | BttrLazyLoading
description