It matters what you plan to use it for. I have owned a terrapin and they are the best for a straight up distance. They do nothing else. Not even angle for shoot to range. If you plan to use it for hunting that is not what you want. I sold mine and got a G7 BR2 range finder. Works just as good on game to distances past where I would shoot and gives you a ballistic solution instantly. For hunting its awesome. If your at the range or playing elr, a terrapin and kestral would extend your range but it takes time to figure your solution. The BR2 actually ranged farther when snowing.
That must have been an older Terrapin unit. Mine has an angle to target setting. FWIW, I upgraded from a Sig K2 to the Terrapin.