Yea, I understand in having to replace every time you take off the balance tube but mostly my point is how much vendors jack up the price on simple simple things. I believe i have found OEM compatible o-rings made from Mil-Spec Viton. Just need to do a little more research on the size and thickness needed. As for the plates.... after a little more research i found CNC machined block off plates for $9 dollars. Don't get me wrong... I'm all for supporting the Z community and buying quality non copied parts from vendors that are reputable and support our community also. In fact, my online shopping cart is at about $1000 just in maintenance parts alone as we speak. Anyways.... I'm just not into paying $20 for something thats is worth less than a dollar (per O-ring). Once i get the chance to do a little more digging around I'll share what i found with the Z community for those O-rings.