The 1000 series syringe is a mid-volume Gastight syringe.
Gastight syringes are ideal for dispensing both liquids and gases. They have a precision-machined polymer plunger tip, often PTFE, which creates a leak-free seal. With the tight fit, the tip essentially wipes the interior of the syringe barrel free of sample. This feature is useful for samples with dissolved or suspended molecules because it reduces the chance a deposit will occur and result in a damaged plunger.