We have not had any RF testing within a closed environment besides our own little machine we bought. Since we have been around for some time in the industry we have seen the “other” metal cases come and go with the said claims. With our current 6063 T6 aluminum alloy on top of the TPU we have had a significant reduction in RF blockage. During our own testing we were 95% of the time less than 5% interference. But several times it was higher with the bumper than with it off! We used several iPhones on Wifi/LTE/LTE OFF.
Lastly, we have had several reviewers and product testers use the K11 and have not noticed an issue at all. These are large press releases that test tons of products (many metal) that give us the reassuring confidence in the long process of perfecting the build. This is on top of the dozen prototypes we have out that are on all carriers and have not noticed a decline. Let’s just say we are proud!
Thanks and hope you back us.