Cylindrical spongescover the inflow holes of filter pipes to prevent tiny animals from getting sucked in and trap particles and debris. They also function as small bio filters.

Small: 1 cm inner diameter, 2″ length

Medium:1.5 cm inner diameter, 2.75″ length

Large: 2 cm inner diameter, 3″ length

The sponges stretch so theyshould work for pipes that are +/- 5mm from the inner diameter of the sponge.