T:Slim vs T:Flex cartridges

Does anyone what is different between the t:slim and t:flex cartridges? Specifically, I was wondering if a t:flex cart can be used with a t:slim. Thanks so much!

doesn’t Tandem have an online store where u can check those items?

The flex pump is larger than the slim. I would imagine the cartridges are different sizes. Calling Tandem directly and asking them was apparently too easy.

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Yeah, it’s 0.2 inches thicker. But the bulge sure looks like it’s just added on to the back, without otherwise affecting the contour. But it would be easy to make it different but not apparent.

I’m not sure I would get a straight answer from Tandem. I’m sure the CSR’s script is to deny and discourage, liability and all. They may be prevented from publicizing that by the FDA. There’s a real possibility that the FDA may require it to be incompatible with the t:slim.

Beyond that, if it does fit, I wonder how the software would behave.

I think they should make a high capacity cart for the t:slim. Best of both worlds.

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I just found this:


They seem to be selling t:slim carts for use in a t:flex. They call it a t:flex 3 ml, but the description seems to say its a t:slim cart and will work in the T:flex.

What infusion sets are you using? Tandem started using a proprietary connector a few years ago, I believe the T:flex was already discontinued at that point.

I’m using the AutoSoft 30 w/t:lock. They still sell t:flex cartridges and they make them with t:lock. They say they will sell supplies until the last tflex warranty has expired.

I guess EHCS is supporting the t:flex beyond when Tandem stop making the carts.

That site lists those cartridges as 300 unit capacity. The tflex was more than that, I think 409-500 units. The regular tslim holds 300 units.

Yes, I know. The point is that they are selling t:slim carts to use with a t:flex. That implies they are interchangable. My guess is that when the t:flex supplies dry up, they suggest that t:flex users can use the t:slim carts.

Flex cartridges hold 480 units. A t-slim cartridge will not fit a t-flex. There is an alignment pin on the end of the pump that is slightly off set on the t-flex. This prevents the cartridge from seating if tried in the wrong model.

I’ve had a t:flex pump for the past four years. The t:flex cartridge will not work in the t:slim pump - way too big. I don’t know if the reverse is true. I would like to try a t:slim cart in my t:flex, since I can only use 300 units of FIASP in the pump without occlusions. But my t:flex warranty expires in less than a month, so I’ve started the Medicare wheels slowly turning to get a new pump, which will be a t:slim X2, unless Medtronic announces that their CGM can be used for treatment devisions without a finger stick. In that case, it may be a horse race. I much prefer a disposable battery over a rechargeable one. I’m frequently away from shore power and recharging is a pain, even with my Jackery.

It’s a shame Tandem pulled the plug on the t:flex. But I understand the business reasons for it. And the t:flex has been the ugly stepsister of the t:slim all along. No updates, no radio, etc. If Tandem had kept the t:flex technologically up-to-date as they did the t:slim, they would probably have had a very viable product.

THAT’S the answer I was looking for! Either that site offering t:slim for use in the t:flex is lying or they have a 300 ml cart for the t:flex.

I think they should offer a large capacity cart for the t: slim.

The site in the link confused me. I believe it is a typo because to my knowledge there is only one cartridge that fits the T-flex and it holds 480 units.

It would be nice if there was a larger cartridge for the T-Slim since they have discontinued the T-Flex. Except for the cartridge the two pumps are the same dimensions. If not for the difference in the alignment pin I believe the cartridges would fit, although I question how the software would handle a cartridge of the wrong volume amount.

Like I said, I originally thought they positioning themselves to support t:flex users after it’s EOL. But you obviously have experience with the difference between t:slim and t:flex cartridges: that they are not compatible. It could be a typo, or wishful thinking w/o due diligence, or an intentional deception.

My guess is that the FDA required the carts to be incompatible since capacity is defining difference between the two pumps. I think you’re right that the t:slim firmware is not set up to use a 480 ml cart. I would hazard to guess that it would indicate empty after 300 ml. But one could go through the load operation to use the rest.

I completely agree that Tandem should make a high capacity cart for the t:slim. As I get older, I use more and more insulin. I’d love to have a bigger cart.