... resistant(-50~200,sterilizable,ametabolic,keep fresh) (2),Measure up to FDA and LFGB standards,harmless to baby . (3 ... bottle. The lower secondary collar holds the bottle, and flow filter in place, while the main collar includes the cap ... bottle comes with a slow flow silicone nipple and a flow control filter. A flow control filter controls liquid flow, prevents nipple collapse, and reduces ...