This is a PP material pipette or dropper. The closure size is 18mm TE, it has a protective ring below the closure part, we also call it tamper evident pipette.
Fit Boston Glass Bottle
Tamper Evident
18mm Tamper Evident Closure (18mm TE Cap)
customize color
closure color and bulb color can be customized
dip tube options
glass dip tube and plastic dip tube options glass tube length can be customized