Recently I had to send my Labradar in to the company to have the wire for the screen reattached. Still worked with the phone app, but no display was showing. I received it back right away, and they enclosed a nice note. One of the comments was that with the SD card I was using the unit took a long time to start and a long time to write to memory. Their technician suggested I upgrade and get a larger card for better performance. I bought a new SanDisk Ultra 16GB card: https://www.amazon.com/gp/product/B00M55BMKK/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 Today was the first day to use it and I have to say WOW it works so much better. I used to have to wait 3-5 seconds for it to display a speed, and it used to be really picky about where the muzzle was in relation to the unit. I had instant readings today, and no missed readings, which is a first. So, if your unit is not working as well as you'd like, consider a faster/larger SD card as an option.