Dexcom G6 sport sensor support

support for the dexcom G6 blood glucose sensor.
useful for doing sports and keeping your sensor safe.
the model is designed to use a 20mm elastic(https://www.amazon.it/gp/product/B0B9B8YJGB/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&th=1).
in PLA it will be a little fragile, we recommend molding in TPU for greater durability (but lower aesthetic result)