volume 0.2 mL, clear glass insert (with plastic bottom spring), O.D. × H 6 mm × 29 mm, pkg of 100 ea: Pricing: 29436-U: volume 0.25 mL, clear glass insert (no spring required), conical point, O.D. × H 6 mm × 31 mm, pkg of 100 ea: Pricing: 29437-U: volume 0.3 mL, clear glass insert, conical point, O.D. × H 6 mm × 31 mm, pkg of 100 ea: Pricing