1.9 inch

Functional Cleaning Tool: Can probe into the bottom of the milk bottle and fit at any angle, Bottle Cleaner Brush is powerful in decontamination, full of dense and elastic antennae. Extensive Application: Ideal for baby bottle cleaning, Baby Bottle Brush can be applied to sports kettles, goblets, water glasses, glass bottles with a narrow neck, stainless steel thermoses, and wine bottles, designed to go deep into every corner of the bottle and clean them properly.