I have bought these off the tool truck, machine supply shops, hardware supply etc etcTook a chance on these- I have to say I was impressed by the quality of the the backer rubber- quality rubber flexible yet supportive, like a temper pedic or something not too soft, not to firmAluminum core, brass insert, and looks like cast zinc and I would say a perfect compound for the backing makes this my favorite one yet.The 2 posts that come with each one… was expecting some cheap chrome plated chinism metal that had the weight of plastic! BUT I was amazed that they had some weight to them, felt great. They look like they would be cheap- but they aren’t.Honestly I handled both of these pieces for a couple days in amazement. High quality!This is what I expected off the tool truck- but I did not get.I always hated the prices of these at stores, so much for the cheapest gumball machine crap.These are by far the best I’ve seen or felt