A connector (50 150 180 200 300 350 400) for use with a reservoir (20 100 220 320 368 420 700). The connector comprises a main body (52 152 182 202 252 302) defining a bore (54 184 254 304) extending from a proximal end (58 186 258) to a distal end (56 188 256) of the main body. The bore is configured for receiving the reservoir. An inner wall (154) extends from the proximal end to the distal end. At least a portion of the inner wall is configured for attachment to an outer surface (22 222 422) of the reservoir. An outer wall (156) extends from the proximal end and the distal end. The outer wall is configured for attachment to a drug delivery device. In one arrangement the outer wall is configured for attachment to a cartridge holder (100) of the drug delivery device.
