This is a true mixer, not a stirrer. The two vertical blades confine the mixing action within the mixing head while the horizontally opposed blades force material from the upper and lower areas of the container to inside the head. The ring prevents damage to the blades and from puncturing container walls. jiffymixer 40" Jiffy mixer, for 10-50 gal. Requires a 1/2" drill. PS-2Regular price: $61.45Sale price: $55.28 21" Jiffy Mixer (2 - 5 gallon capacity) Requires a 3/8" drill. ES$40.82 15" Jiffy Mixer (1 - 2 gallon capacity) Requires a 3/8" drill. HS-2$13.18 10" Jiffy Mixer (pint capacity) Requires a 3/8" drill. LM$10.26