Can someone smarter than me explain why this laser thermometer gun https://www.amazon.com/dp/B00837ZGRY/?tag=exoticpetnetw-20 —now marked “not for human use”—is radically different from this one: https://www.amazon.com/dp/B087TTL5C3/?tag=exoticpetnetw-20, other than costing $75 less?