Like to ask what these are called

[Allanzkie2017]

Hello, i would like to ask what these black spring holders are called.
i just bought the motherboard second hand, this is an ASUS Z87-K Motherboard and one heatsink was missing with that black spring holder.

thanks in advance

http://i.imgur.com/W7MtSiG.jpg

http://i.imgur.com/F6if7Gd.jpg

 

[alexoiu]

Hi,
Spring-loaded screws,
or https://www.alphanovatech.com/en/cat_attach.html
or http://www.myheatsinks.com/products/heat-sink-attachment/
or similar.