They've been produced with the help of Italian designer and noise artist Nicola Vinciguerra and come in red and black. They're 69 kuai and are available on Taobao here.
I'm actually a big fan of bands doing their own merchandise like this. It's a good way for them to make a bit of money and I find people often ask me about the bands when I'm wearing the t-shirt which then means I can tell them where to find their music and see their shows. I reckon having Torturing Nurse emblazoned across your chest is going to be a conversation starter wherever you wear a t-shirt like this. So if you buy one and someone asks you about it, you can send them a link to this post right here, which I'd say is a nice introduction to the world of Torturing Nurse.