Here's the kit that i got and an explanation of each one so if you wish to purchase these amazing brushes yourself you can pick which ones you want =)
If you dont own or know about sigma all their face brushes start with 'F', eye brushes start with 'E' and precision start with 'P'. This is the 'F82 - Round Kabuki' This is for buffed foundation application to blend mineral products into the skin.
'F80 - Flat Kabuki' Buffed foundation application for liquid or cream products. (Thee most amazing foundation brush you'll ever buy. Makes liquid look like its skin, and builds product well)
'F84 - Angled Kabuki' - To blend cream blush or bronzer onto the skin (i dont like cream products on the skin but this works ana brilliant contour brush)
'F86 - Tapered Kabuki' - Precise concealer application, exact placement of concealer on harder to reach places.
With the it i got a free eyeliner brush the 'E11'. I've always used an angled brush for my gel eyeliner but this is really well shaped and i got better results of winged eyeliner than with an angled brush.
**Please note the opinions are my own but the decriptions are from Sigma themselves**