Unique ultra-low draft construction of inner diameter
yields high accuracy and stability. They are comprised
of industry compliant silicone and chloride free, low
friction polypropylene. Available in three different
colors: Natural for most generic applications, amber
provides protection of UV/visible light block (up to
520nm), but with the ability to see material inside the
barrel; and black for total light block. Sold in bulk and
packs of 50.