This is NOT a standard tool
As remarked by another reviewer. This is designed for Yankee Hill free floats. I gave it 4 as is it not a wrench tool for ALL AR's. Also, when tightening the jam nut. Painters tape and great care must be taken to prevent marring of the jam nut. If you do a lot of Yankee Hill free floats. This is a nice tool. As an FYI. Many free floats use their own mount tools. Only Milspec original parts take generic armorer tools. When you get in to free floats or .308 caliber. They all use their own hole pattern and custom mount design. One of the nice features of many YHM free floats is the anti rotation screw models, which ensure a solid mount system for M1913 standard rail platform.
Necessary, costs too much
This tool works perfectly if you follow the directions and use it for what it was intended. It is NOT intended to take old barrel nuts off - you need an armorer's wrench for that. There is no way to measure torque with this wrench. YHM recommends that hand-tighten their barrel nut and then turn to the next available hole for the gas tube. If you prefer to verify a min. 35 ft# you need an armorer's wrench that allows for the attachment of a torque wrench. This tool has one function - it is to engage the recesses in the locking collar to snug it tight. You can make other tools work, but this is the only one that works properly. For it's very limited function it costs too much, but as with the the special wrenches for, e.g. the Daniel Defense rails (which wrenches also cost too much for what they are), you're paying for a professional install, not for the tool itself. NO, I would not recommend it to a friend because for the cost, I'd let him borrow mine. If you can borrow it, do that.
might be needed
a previous comment was that a good armorer's tool will do anything required of this 'forearm wrench'. i almost believed that comment, but i bought the wrench anyway and was mad at myself for doing so(because i have so many tools)until i went to tighten everything down. i found this wrench to be very important to me.
