A syringe and detachable needle assembly having binary attachment features include an elongate syringe barrel having a longitudinal axis, an open proximal end and an open distal end including a collar. The collar includes the cylindrically shaped sidewall having an inside surface and an outside surface. A needle assembly includes the hub having a body portion including a proximal end, a distal end and a conduit therethrough. A cannula having a distal end, a proximal end and a lumen therethrough is attached to the distal end of the hub so that the lumen is in fluid communication with the chamber. A lug is provided on one of the collar and the hub and a ramp and a rest surface is provided on the other of the collar and the hub. The ramp is oriented at an acute angle with respect to longitudinal axis for guiding the lug during needle assembly attachment, to the rest surface forcing the hub to contact the barrel to form a seal the hub and the barrel.
