I bought this crimp tool to make an extension cable for a Yaesu FT-7900R transceiver. I purchased this tool kit as it was Amazon's choice on the search. I followed the manufacturer instructions that came with tool and watched several YouTube video on how to crimp the connector onto the tool. The RJ12 jacks are six wires and I called Yaesu the manufacturer of the radio and they told me I could make my own cable with the RJ12 ends on it as long as the colors match on both ends of the cable (straight through cable). I made my colors: green, green white, orange, orange white, blue, blue white. I did not use brown or the ground on the Cat5e Cable. I used the supplied crimper from this kit and tested the cable with the supplied cable tester. I checked each end of the cable 3 times and it passed. I then proceeded to hook this up to my radio and BOOM the problems started. The radio would not power on. When I unhooked the cable I noticed the pins on the female end of the socket were bent. See attached photo. The RJ12 on the left was with a new crimper I bought from Lowes. The one of the right was with the crimper from this kit and you can see the brass teeth are on an angle, higher on the left side of the plug and lower on the right side of the plug. Turns out these pins were not properly crimped and Pin 5 and 6 managed to short out inside the radio sending 9 volts into a 5 volt circuit. I took the radio to Greenbrook Electronics in NJ. The tech currently has the radio and I received a verbal estimate of $200 for the repair to change out the voltage regulators that were damaged on my radio. The tech will give me a written estimate later this week. Amazon offered to give me $50 towards the repair, but I told them it is not their fault- the crimper is defective! I will trying reaching out to the company tomorrow so that they can pay for the damages they caused.Update on 10-6-19. I called the company spoke to Frank/Michael and he stated my case is under review and that someone would call me back. I am currently working with Ubigear to find out why my particular tool is defective. With no wire in an RJ12 connector it makes nice horizontal crimps. Add wire and they look jagged like a staircase. The plastic between the pins almost won't exist which will cause a short. I sent the product back to Ubigear and they are reviewing my defective tool. Also looking to work this out with them to assist with paying for the repairs. So far their customer service is A++. Update to follow soon. Radio still sitting in a repair shop pending Ubigear's investigation. Cost is $223 to repair my radio due to a 5 and 6 pin short from this crimper.Update on 10-17-19: I have been playing middle man back and forth between the radio repair shop and Ubigear. It's very tiresome to constantly be messaging daily and calling the repair shop with updates. Very long and drawn out process. Ubigear tested RJ12s after I sent the crimper back- picture slightly blurry went sent to me as it was a screenshot of a video. The pins to me still looked bent. Ubigear claims crimper is fine. When I had it I made about 12 to 20 crimps and cut all but two off of the cable, that's how bad they were. I would not purchase this brand crimper ever again. Maybe the tool is a good value but the one I received was defective. Seems it was cast improperly. Solely based off of Michael's response to the issue and the willingness to cover $50 towards the repair I an upgrading this to 3 stars. We both have differing opinions on this matter but Ubigear made it somewhat right. Would have been 5 stars if they stood by their product and covered the repair.