Beaded rim These test tubes are well annealed, resistant to heat and chemically stable. Rims are fire-polished. The 25mm tube does not have a marking spot.

With lip Tubes 10 mm through 18 mm o.d. have marking spot. Listings indicate length x o.d. in mm.

Fabricated from specially selected tubing for product durability. Engraved white-filled graduations at 25 and 50 mL .