Port plug 19/25, phi18.5 (for volumetric cell)
https://www.scientificgear.shop/shop/k20-08151-k720-3130-port-plug-19-25-phi18-5-for-volumetric-cell-29796
https://www.scientificgear.shop/web/image/product.template/29796/image_1920?unique=48946a0
Port plug 19/25 phi18.5 1/10 taper glass