Holder for cartridge-needle unit

A holder for use in combination with a pre-filled cartridge-needle unit having a circumferential ring, said holder comprising:

• a hollow body sized for housing the cartridge-needle unit therein having proximal and distal ends, said body comprising a pair of squeeze pads disposed on the distal end thereof;
• and
• means for permitting the body to move axially relative to the cartridge-needle unit between use and safe positions;
• the improvement wherein said body comprises a pair of cam slots at the distal end thereof and a pair of retaining slots at the proximal end thereof, said slots being sized to accept said circumferential ring and positioned to hold said cartridge-needle unit in use and safe positions
• and wherein the distal end of said body is elliptical in cross section, said ellipse having a major axis substantially longer than its minor axis and the proximal end of said body is circular in cross section and said body is tapered from said distal elliptical end to said proximal circular end.