Why no single bottles if Piezography anymore?

I have been ordering CC PRO and substituting the LK & LLK with Piezo SEL4 & 5. I just went to place an order online(so I could use the promo code) and there was no option to order the single bottles. Why? The only one I found was for 4.5?

Do you means these?

We ran low on the basic ingredients but are back in stock and I made another Pro run a few weeks ago. It takes a bit of time to bottle and warehouse.

They will be back online on early next week. For now anyone who is a pro customer can order by emailing sales (at) inkjetmall (dot) com. We keep back stock enough for anyone who has a current system to continue to order ink.

best,
Walker