Check the listing for details. Aquarium Co-op: Pre-filter Sponge. Condition: Brand New. Listed at 9.47 USD. Aquariumco-op: Pre-filter Sponge. The center hole is closed at 1 end. The pre-filter sponge is placed over the intake tube of hang-on-back and canister filters to prevent small fish, debris and other objects from entering the filter and potentially damaging the motor. It also provides a surface for beneficial bacteria to grow and helps to purify the water, making it safe for your fish to live in. In addition, it extends the life and efficiency of your filter media by providing mechanical filtration. Dimensions: (approx) Large: Outer:15x9x9cm Inner: 11x3x3cm Medium: Outer: 8x6x6cm Inner: 7x2x2cm Mini: Outer:8x4x4cm Inner: 6x2x2cm Multiple item discount: If you are interested in purchasing multiple items, we would be happy to offer a discount. Please send us a message with a list of the items you are interested in and we will create a personalised listing for you with the discounted price. Combined shipping is also provided. A personalised listing is a listing where your name is added to the title of the listing. It will include the discounted price for the items that your interested in purchasing. The description and/title will contain a list of the items. The link to the listing is emailed to you via ebay. We look forward to working with you! Shipping: We offer free shipping for orders over $100. For orders under $100, calculated shipping will be applied. If you are interested in purchasing multiple items and would like to take advantage of combined shipping, please place all items in one transaction and contact us prior to purchasing for an estimation of the combined shipping cost. The combined shipping cost will be based on the weight and dimensions of the items being shipped and will be calculated at the time of checkout. If the combined shipping cost is less than the amount charged, the excess will be refunded through eBay. Tracking information will be added to eBay upon shipment.