Rossmont Mover MX4100 Circulation Pump (2 pack) Waver Controllable: This pump may be controlled by the Rossmont Waver Controller.(Not Required For Use) TWO 4100 gph MX4100 Circulation Pumps Dimensions: 3.12" X 3" X 3.25" (pump only). The pump with the magnet holder will protrude into the aquarium 3.75". Timer compatible Includes magnet holder suitable for glass up to 3/4" thick