There are 2.5 and 3 gallon bottles for samplers as well as 5.5 and 6 gallon bottles - What size are the bottles actually?
Sigma Sampler Bottles
The specification for what the bottle will hold is 3 and 6 gallons. Nalgene only marks the bottles with the highest value of 2.5 or 5.5. In some of our literature you will see 2.5 and 3 gallon, but then also 10.4 liters. You will usually see 5.5 gallon or 20 L for the larger bottles. We typically want to describe these as 3 or 6 gallon bottles to prevent confusion.