Reflection falling below 4%

I have 2 Garadget’s over a year now. Front garage reflection has always been 90% or more. However my back garage has been sending false opening and closing notifications the last 2 weeks. Today it’s off the charts. I tried switching the reflective tape and no help, slightly better in the dark but hovering around 6-7%. After reading the other Posts regarding weak reflections, I’m pretty sure my laser is loosing it’s mojo.
How can I order one and does it require any calibrations if I were to replace it?

John,
There is no need for calibration because Garadget does that continuously in the software. For instructions on replacing the laser at home, please see this post: