I was looking for a trimmer rack recently as well. I looked at the one at TSC and several others.
I talked to some local people that had racks and they told me that those kind would damage the handles on trimmers from bouncing and rolling. I instead bought the Xtreme one.
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It actually has two aluminum hooks that bolt to your trimmer and it does not bounce or roll in the racks. I have not had mine but a month or so but I have talked to a guy that had one for a good while and he said it was the only way to go. It locks with one lock and does a great job so far.