The invisibleSHIELD designed by ZAGG to protect iPhones is now available for iPhone 4, complete with 0.2 mm thick strips to cover the phone’s stainless steel frame, which doubles as the antennae. The strips are dubbed Side Shield, and they are now provided free of charge to Best Buy customers purchasing an iPhone 4.

A loss of signal strength and, in certain circumstances, dropped calls and data connections has been attributed to placing the hand over the antenna on the left-hand corner of the phone. The invisibleSHIELD, now available for free to buyers of an iPhone 4 through Best Buy, should help alleviate said reception issues, according to an announcement issued by the retailer today.

“Consumers are looking for immediate solutions and the Side Shield is a great option,” said Scott Moore, vice president of marketing for Best Buy Mobile. “At the same time, we know that customers are always looking for ways to personalize and protect their smart phones. That’s why we are so focused on having multiple options—people want to choose what’s right for them.”

“ZAGG has conducted extensive testing to determine if our products can help this problem, including internal tests, independent lab tests, and research with with consumers in the wireless industry,” the company says on its web site. “Although the signal strength bars may still decrease from your hand covering the antenna, our results show that each of our solutions help prevent dropped calls and data connections.”

The offer is available starting today. The invisibleSHIELD comes in the form of a clear, unobtrusive shield applied to the outer edges of the iPhone 4, addressing issues with antenna attenuation. This program will be available free of charge, including installation, to anyone who purchased, or plans to purchase an iPhone 4 from Best Buy. 20% discounts are also available for iPhone 4 buyers looking to get a protective case. Apple, however, will provide one for free to every iPhone 4 owners through September 2010. Customers only have to download an iOS app and use it to choose their preferred case model, including Bumpers (manufactured by Apple).