These cables seem to be well made and are certainly reasonably priced. However, they may not be what you're looking for. These are NOT Ethernet extension cables, they are CROSSOVER cables. In the description where it says "connector type A" on the female end and "connector type B" on the male end, what they really mean is the male end is wired to EIA-568B and the female end is wired to EIA-568A, which amounts to a crossover cable. So, if you're looking for a straight extension cable, these won't do the trick. Furthermore, if you think you can just hook two of these up in series to end up with a straight-through result, that is not the case either (doing so will result in a polarity reversal on two of the pairs).If you need an extension cable and you're willing to do some work and you have the necessary tool to install a new connector on the male end these cables could be a decent starting point since they have a nice molded female connector on one end already. Just lop off the male connector, prep the end as appropriate, and crimp on a new male connector. Be sure to install the wires as per EIA-568A on the male end an you will have a nice male to female Ethernet extension cable.This sounds like a bit of work (and it is) but male to female Ethernet extension cables are hard to find and female RJ-45 connectors designed to dangle from the free end of a cable (as opposed to panel mounting) are also difficult to find. Keystone RJ-45s are readily available but don't lend themselves well to making an extension cable. Female Industrial Ethernet connectors are bulky and pricey. That leaves converting one of these looking like a pretty good alternative. Of course, another way to do it would be to use a standard male-male cable and a straight through RJ-45 coupler. Cost-wise (assuming you have the tool and your time isn't too valuable) modifying one of these may still be an attractive option.
MCM Electronics gave me terrific service and great prices. I will cheerfully shop with them again for my electronic needs.