订货信息: 订货号 描述 4-000-220 Pipet-Aid, Plain, 220 V, CE 4-000-221 Pipet-Aid, with Dual Pump Filtration Unit, 220 V, CE 4-000-220-TC Pipet-Aid complete with T.C. Nosepiece and four extra Filters,220 V, CE 4-000-221-TC Same as above but with Dual Pump Filtration Unit, 220 V, CE