Replacement for the 13mm Gardena Tubeholder - Ground pin which is phased out and not for sale anymore.
It is a perfect fit for the old style sprinkler t-joint.
Print in PETG for best result / strength.
Many thanks for the original design.
The author remixed this model.
Made changes to the inner structure to match the original Gardena part. This will hold the Sprinkler T-Joint better in place.