Qorpak GLA-00856 Glass Clear 4oz (120ml) Oil Sample Bottle with #6 Cork. Clear oil sample bottles are provided with a #6 cork and feature a unique design. These clear bottles are ideal for field analysis in the petroleum industry. The design of this bottle also makes it an excellent choice for displaying product samples. Oil sample bottle with #6 cork. Measures 37 millimeters diameter by 163 millimeters height.