Sapphire HD 4870 & PowerColor HD 4870 - what’s the difference?

I was planning to buy the Sapphire HD 4870 (Sapphire HD 4870 512MB GDDR5 Dual DVI TV Out PCI-E Graphics Card - Ebuyer), but that has recently gone ‘out of stock’. The alternatives on the site I can see are the PowerColor HD 4870 (PowerColor HD 4870 512MB GDDR5 Dual DVI HDTV Out PCI-E Graphics Card - Ebuyer) and the Gigabyte HD 4870 (Gigabyte HD 4870 512MB GDDR5 Dual DVI HDTV Out PCI-E Graphics Card - Ebuyer). Are these all the exact same graphics card? What (if any) is the difference between the