I will not use the labradar unit, I test every new load, rifle, pistol, crossbow, longbow over a chronograph. My daughter just killed my Prochrono, crap happens! They will send you a brand new one for something like 82 bux plus shipping if you send in the old dead one. I bought a new DLX because I wanted it the next weekend, but will send in the old one and shelf the new one, it will happen again.