Klein Tools are known for their excellent quality tools so I bought this stapler because of their reputation. What mistake. I can't understand why it's so bad to use. I use about half the staples every time I use it. Staples just don't sink into the material. It works well, sometimes on drywall, but I mainly use it for category 6 cables and if the brace is stuck in the wood at all I have to use a light hammer to get it firmly in place. In most cases, the bracket will simply fall out or pierce the cable. I have the same problems as others. First the stack of staples is straight in the hole, I have to insert the stack into the spring element in the area of the staples. With most staplers, you open the guide, place the staples on it, push it back in, and lock it. Not this thing. Even with my fingers on the top area where the stitching takes place, I can start pushing the staples back into that little springy track, guiding the entire piece inward and locking it. If you just look at the brackets and where the brackets come out you can usually see that the brackets are not centered. This is a problem as I have found that the staple often goes through the wire. Therefore, after stapling, I have to constantly check whether the staples have moved. At the front of the stapler where the staples come out is a metal guide that can be lowered. This guide is shaped so that you can hold the cable in this slot to keep it from moving. However, I can't tell you how many times this part is just useless because I can still find staples that come with a real cable. I also use about 4 or 5 staples out of 10 each time. This is because the braces just don't penetrate most things I use them on. I mean, most of the time they don't even flex, they just fall off whatever material I'm attaching them to. I run ethernet cables inside and outside the house. I've found testing staples on drywall to be the most successful staple material. However, no cables need to be stapled to the drywall. I have a 2x4 for framing the walls and exterior wood of the house. I also had to staple the pressure treated joists under the deck. As I have already said. I have to use a light hammer to push the staples in even more as they don't usually go far. I can't explain how this stapler came onto the market. I have also bought all sizes of insulated braces from Klein and the problem occurs with all braces.