A kind of attachment being used for injection pen or syringe, the attachment could attach to the needle or backshank of injection pen (7) or syringe, the attachment includes the circumference array for the flexible fingers (9) being inwardly directed to, the flexible fingers being inwardly directed to are arranged so that the flexible fingers can be bent axially and inwardly to facilitate the aggregation of the fold of subcutaneous tissue near needle insertion point when flexible fingers tip is against injection site pressing.
