Float Switch Holder -Allow to control the pump manually. When the pump is at this manual mode, it can pump water as low as possible. Just do not let pump becomes dry running at this mode. Solid Passage -The pump is designed also to work with dirty water. Its Maximum solid passage is 35 mm. So it will be suitable for mostly water conditions for your daily domestic application. Small sand, some muddy water, or particle all can pass through the pump. Space Size needed -It's better to have a sump or tank size 50x50x50 cm, so that the float switch can be freely floated in the water. Performance Data -The maximum output with 50 mm discharge port is 13 CBM/H. Owner's Manual-Please read the owner's manual before use. TOPEX 750w submersible water pump is great for draining garden pond, water tanks, pools, flooded areas, etc. It will be a necessary tool for every house. The pump is designed also to work with dirty water. Its maximum solid passage is 35 mm. So it will be suitable for mostly water conditions for your daily domestic application. Small sand, some muddy water, or particle all can pass through the pump.