3d printed Glock holster designed for model 17 but it should fits well for the other models. Assembled by 3d printable parts. There are three types of catch or attachments: 25mm for molle standard, 40mm for belt, 40mm extended.
Commercial parts you need to buy is: couple of screws with nuts, spring and 4 mm diameter pin.
I use 0.5mm nozzle diameter extruder and it works well.