Dummy not spotting the diff

[THE DOC]

Hi there im coming across a bit dummy here
can anyone tell me the difference between these mobo

Gigabyte GA-P55-UD4 Intel P55 (Socket 1156) DDR3 Motherboard [GA-P55-UD4]
Gigabyte GA-P55-UD3 Intel P55 (Socket 1156) DDR3 Motherboard [GA-P55-UD3]
Gigabyte GA-P55-US3L Intel P55 (Socket 1156) DDR3 Motherboard [GA-P55-US3L]

i will not be overclocking just the difference in price for me
im looking towards getting this chip [Intel Core i5 750 2.66Ghz (Lynnfield) (Socket LGA1156) - Retail + Operation Flashpoint: Dragon Rising Game [BV80605001911AP]

 

[Zenduri]

Job done.
Pay attention to the PCI/PCI-E slot and what speeds the pci-e run at thats where your main difference is and the ud3L and ud3 don't have e-sata and have less sata ports
Board comparrsons

 

[OrphanBoy]

The UD3L is also narrower than the rest. Check the dimensions and pictures!