Generally, we recommend choosing the G29 / 10 mm needle length to give an ideal placement into the subcutaneous adipose layer; however, for thin patients, the G29 / 8mm is more appropriate as there is a risk of the needle being placed in the subcutaneous muscle. G27 is a wider bore needle and is used for more viscous drug preparations (i.e. immunoglobulins). The different tube lengths accommodate the needs of patients and position of the pump. Please consult drug and pump manufacturer instructions for use prior to choosing the appropriate infusion set.