An unusual syringe

I have finally finished administering the course of fourteen injections in my abdomen, which is now covered in bruises. Thank goodness that´s over.  The syringes I used looked very unusual, at least to me, I´ve never come across anything quite like them before. I am used to the common or garden type with a barrel, plunger and needle on the end. Maybe I am out of touch.

This is an example of a used one with the yellow plunger fully in. You buy them already containing the medication, ready to use. After giving the injection you give the plunger an extra squeeze and a tube shoots out to encase the needle. You can see the coils of the spring which causes this to happen in the photo. I can only imagine this elaborate precaution is because most homes don´t have a "sharps" container for the safe disposal of used syringes. Since you can buy over-the-counter disposable syringes in any pharmacy here that would seem to be overkill to me.