These upward flow attachments are for the UF series non-aerating upward flow stirrers, item #21024 which are sold as motor drive units only.
The smaller one will work in 25 mm test tubes, requires a minimum volume of 12 mL in order to avoid aerating the solution, and has a maximum volume of approximately one liter. It is ont advised for viscous solutions. Diameter: 0.75" (19 mm). Overall length: 9.5" (241 mm). Weight: 0.8 lb (0.36 kg).
The larger one works with vessels from ~250 to 8,000 mL with a maximum viscocity of 3,000 centipoise. Diameter: 1.5" (38 mm). Overall length: 12" (305 mm). Weight: 1.5 lb (0.68 kg).