Sorry, the time of our PTH-9A detector uses a 24-hour clock and cannot be changed to a 12-hour clock. Hope this information is helpful to you. 

First adjust the focus, then aim the lens at the target, observe through the glasses and adjust the focus until it is clear. 

(1)Please check to make sure you have installed 1.5V 6*AA battery. Do not use inferior batteries as their voltage is lower than 1.5V. (We recommend brands like Energizer, Duracell, AmazonBasics, etc.). (2)Make sure the polarity is correct and the contact with the spring is normal. (3)Press and hold the power button for at least 3 seconds to power on. (4)If it still cannot be turned on after 1-3 steps, please try to use a power bank. 

This monocular is very useful to look faraway. My kids love it very much and use it to watch the airplane and the seagulls flying through the sky.  

It’ll be fine for 50 feet! I’m not sure of the exact range but it works great at 50.