Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Didn't work on Yukon NVMT 4 x 50

I got this to compliment the Yukon NVMT 4X50 that I got but when I put it on, it would not focus at all. The focus adjustment operated properly but there wasn't enough range to bring the image into focus. I put the 4X50 lens back on (which worked fine) and decided to send them both back. he NVMT is a decent Gen 1 unit so I think I'm going to order the Yukon Sea Wolf 3X42 and stick with that.