I use https://www.amazon.com/dp/B08L7HX733/ref=sspa_dk_detail_0?psc=1&pd_rd_i=B08L7HX733&pd_rd_w=Y7iRi&pf_rd_p=7d37a48b-2b1a-4373-8c1a-bdcc5da66be9&pd_rd_wg=eKIHa&pf_rd_r=GMQC7XQ085ZFEX5QJ6ZH&pd_rd_r=566092df-2bab-4c1b-9d29-5f6c4e058112&spLa=ZW5jcnlwdGVkUXVhbGlmaWVyPUEySEtFU0tRN0ZHME1HJmVuY3J5cHRlZElkPUEwNjcxNzY5RTg1MUNSQkRNMFRIJmVuY3J5cHRlZEFkSWQ9QTAwNjgwNDgzR0c0U1lDU1RRT0xLJndpZGdldE5hbWU9c3BfZGV0YWlsJmFjdGlvbj1jbGlja1JlZGlyZWN0JmRvTm90TG9nQ2xpY2s9dHJ1ZQ==

I have a couple - one I just leave as is, the others I've actually attached directly to my various wrist guards (for different temperatures).