Just getting into reloading and just watched the video on the wtf trimmer and was wondering about your opinions on it but my main question is int the video the bench he is using has what appears to be some aluminum or steel channels that are used to secure things to the bench are these on every bench are they needed where do you purchase them do any of you have plans or suggestions for a well designed build for a bench? Probably seems like a silly question but have never seen someone reload before.