Welcome to the forums. The 550M is actually the 580M, it's just typed out, or even advertised wrong. I don't know about the solar panel, but to secure it is something of a joke IMO. You certainly need the included strap. The plastic attachment that you screw on the back with 4 very, VERY small & short screws, and you can only get a Python cable to squeeze thru it. Why HCO allowed this is a mystery to me. Due to those brackets, the cam will protrude from the tree moreso. I use velcro to attach plastic leaves to make the cam blend in to its inviroment all the better. Speaking of security, don't let your cam be in direct sun light, the IR panel covering will create quite a glare.