I noticed the mt-4 drop down is available only in aluminum. The price does not matter to me, but i could see $70-80 being intimidating for some buyers. I think a delrin option would be a great idea. I know delrin can be machined like alumium, but the benefits i could see are: less cost, lighter weight, and more sales due to lower cost. I think you should still offer an aluminum option on both drop downs, but i think a delrin option would be a very nice alternative. It could also be had for around $40-50 i'm guessing. Either way, i would still buy it, delrin or not. Just something to think about.