Roche ACCU-CHEK TenderLink Instructions For Use Manual page 16

Warning
Change the head-set every 2–3 days (max. 72 hours). Otherwise you risk
insulin resistance or inflammation of the infusion site.
Never use the tube-set for more than 6 days.
You must fill the empty space of the newly inserted head-set after connecting
the transfer set. Failure to do so results in missed insulin.
Always check your blood glucose level 1–3 hours after introducing the set.
If the coupling does not click noticeably and audibly together, use a new head set
and a new transfer set.
Do not use any tools to screw the luer-lock connector into place.
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