Can someone tell me the dimensions (length/width) of the rear rack on the RadCity ST?

Just wondering if anyone has one they'd like to sell. They are currently out of stock and not back order-able.

Alternatively, anyone have any other suggestions for a similar basket? I purchased the small basket bag, so I'm looking for something that will accommodate that.

This is for use on a RadCity ST.

I'm awaiting shipment on the RadCity Step-Thru that is due to ship end of June. Meantime, I'm buying some tools and accessories just so I'll have what I need when it gets here. I haven't biked in DECADES, so everything is sort of unfamiliar to me. I ordered a couple of spare inner tubes (Kenda, correct size, same ones sold on site) on eBay (free shipping). When I opened the box, the tubes were inside, as well as some very long, flat rubber strip-loops. They are stamped with the size of the tube and have a single hole that looks like the valve stem would go through. Can anyone tell me what these are for? I could always ask the seller, but thought I'd ask here, first. I can post a picture if it's not clear what I'm talking about.

Thanks!