"...when you’re ready to brew, then you remove your tea bag from the Tsleeve, unwrap the tea bag, and then slide the tag and string through the Tsleeve and through the notch at the top, as shown in the picture to the right.
This is probably the most useful part of the Tsleeve, in my opinion.  On the occasions when I’m brewing tea in a tea bag, the tag seems to inevitably end up in the cup with the liquid as it infuses.  Either the string isn’t long enough, or the act of pouring the hot water into the teacup seems to whoosh the teabag right into the cup with the liquid and I either have to try to fish the tag out with a spoon or fork or I burn my fingertips trying to get the tag out with my fingers.  This ‘feature’ offers a larger ‘anchor’ that doesn’t get swept away into the tides of my teacup."

SRC: Check out the full review of t-sleeve® provided by the SororiTEA Sisters at: sororiteasisters.com/2015/02/03/product-review-the-tsleeve/