Smart Phone Strap Attach

Now that I have a Microsoft Band 2, I don't always have to have my phone in my pocket, just near me. My professional job requires me to have my phone near me at all times. This project was designed to allow a secure way to attach my phone to my tablet bag strap. It was designed for my iPhone 6 (smaller version) with an otterbox case on it which is pretty big so it should fit many phones. The basic inside dimensions are 77mm x 13mm with rounded edges (see pictures). It is a 2 piece deisgn wit