Jiffy PS-1 Mixing Paddle 20.5” The PS-1 model is made for heavy-duty tasks in 5-10 gallons (20-40 quart) containers and is made of 304 polished stainless steel. It is intended for up to a maximum rate of 800 RPMS. It fits any 1/2inch electric drill chuck power tool easily. For the best rate of completely mixing, use tools with 450-750 RPMS . If desired, mixers can be installed permanently.