Air Cooling System ACK-I5361 series Support for Core i5 (LGA1156), Core i7 (LGA1366) & LGA775 socket, Crossbow I5361 provides user more options of installation and appropriately increases fasten force of coolers and CPU. Moreover, the Spring-screw& Back plate (Steel K7 material, 2mm thickness) mounting method can protect the MB from bendingand ensure safe installation when MB moved.