Toluene

Box of Colorimetric Tubes.  124SA/SB = 3 year, 124SH = 2 year, 721 = 1 year shelf life from date of manufacture.

721 = 2x 10 Tubes per box.  Each sample uses 2 tubes. 10 Samples total.

Others are 10 Tubes per box.  Each sample uses 1 tube. 10 Samples total.

721 must be stored in a refrigerated place (0-10°C/32-50°F).