Instruction: Extract information from the supporting document to answer the given question.

Input:
Question: this model doesn't come with a digitizer pen but does the pen work with this model?
Document: This is a good tablet, but be careful to pay attention to model numbers. The one that ends in 23U does not come with a pen. According to Lenovo techs if the tablet does not come with a pen you can not order one to go with it later. (I tried.) This is because in order for the pen to work digitizer chips must be installed in the tablet.
NOTE- be sure the model you order from Amazon has the digitizer pen standard and not as an add-on option.5) Apps for W8 remain a mixed bag. Some work fine (Dropbox), whereas others (Kindle) are pretty poor. However, keep in mind that you don't have to use the W8 apps unless you want to, since you can load the standard Windows applications through the Windows desktop.
This is a great tablet! But be careful. This is the base model available from Lenovo for $649, not the model with the pen and digitizer that sells for $699.Thanks to Amazon for great customer service.
If you don't get a model with the pen and digitizer, you can't add it later. I also believe this is true with the WWAN feature. I've noticed that many of the resellers don't necessarily know which features are included with which model numbers.
Its a shame that Lenovo could not make it clear in products list that a version exists without the digitizer pen. unfortunately that version will not work with any pen although it has a slot which can be opened with little effort to fit the pen which can be purchased separately.
Be aware the model shipped doesn't have a pen, and you cannot add a pen later on, because the screen just doesn't support pen function. Amazon should warn this on the product description.
It all ran with no problems as I was watching a video on a slice of the left 1/3rd of the screen. Best multi-tasking I have seen on a table so far (this is true of any Win8 tablet). Oh, forgot to mention, it was doing all of this while accessing the internet tethered to my cell phone. So, the chip performs just fine.I purchased the Win8 Pro version with the Watcom digitizer pen and screen and happy I did.
If you are using a HD iPad or Asus Infinity, the screen may be an issue, but that is a personal choice.3) Peripherals: Unlike one of the reviewers above, the peripherals I have installed so far have worked fine, including a USB mouse and Bluetooth keyboard. I will try an external HDD drive while I am away and report back on that.4) Pen: I have to say that the digitizer pen is a great addition to the tablet experience, especially when using MS Office.
I purchased a model without a pen/stylus and purchased the stylus separately. After struggling with configuration, I made a quick(!) call to Lenovo, and they told that if the stylus isn't included, you cannot configure that Tablet 2 to use a stylus.I returned it. This should be made clearer somewhere...BTW, calling Lenovo's tech support was surprisingly painless.
I called the Lenovo help line, and it turns out that I bought the model ''367823U''. What? I asked. The agent refered me to a pdf link with a product description and down in the middle of all the pages, it showed that my model didn't have a pen.This for me is nothing short of false advertising, as in every spec, web description etc, I was led to believe that the tablet would have a pen.
Answer: Lenovo tech support claims that if the Tablet 2 doesn't come with a pen, it cannot be configured to work with one.  Buyer beware!http://www.lenovo.com/psref/pdf/tabook.pdf* The models without Tablet Pen can not support pen input function via  ThinkPad Tablet 2 Digitizer Pen (0A33899)