Aesthetic Syringe Plunger 3D Design

I need a 3D-printable file for a device that can be mounted onto the plunger of aesthetic medicine filler syringes.

The device should add only a rear finger ring to the plunger, similar to the ring used in dental aspirating syringes, without modifying the rest of the syringe.

Main goal: allow the physician to perform aspiration/reverse pullback without changing grip during the injection.

Design requirements:
- stable attachment system to the plunger;
- single ergonomic rear finger ring;
- controlled pullback and normal forward pressure;
- compact, lightweight design;
- if possible, adaptable to different filler syringe plungers.

Required deliverable:
- final file in a format suitable for 3D printing.