MILA · Model A · Quzhou, Zhejiang, China Threaded 28/410 Polypropylene Trigger Head with 0.75cc Metered Shot and Plastic Spring The MILA Model A is a threaded 28/410 polypropylene trigger head engineered around one persistent problem: chemical bottles that quietly destroy ordinary sprayers. There is no steel spring inside. Every part that meets liquid — from chamber to piston to return spring — is moulded in PP, so bleach, degreaser, acidic washroom spray and alcohol