Check the listing for details. Replacement Swimming Pool Skimmer Weir Door - 5¾ in. W, 4¾ in. L Fits SP1091. Condition: New. Listed at 15.92 USD. Replacement Swimming Pool Skimmer Weir Door - 5 5/8 in. W, 4 3/4 in. L Item Number: 108529 In order to prevent any debris from escaping from the skimmer basket when your pump is turned off, there is a door that closes the skimmer system off. This door is called the skimmer weir. Without the weir, your skimmer won't skim the top of the water. Fits SP 1091 skimmer; Hayward NEW Style skimmer & weir. Like the skimmer, the skimmer weir adjusts to the water level in your pool on its own. It floats just on top of the water so that it can always collect floating dirt and materials. When you need to replace your skimmer basket or clean it out, you can completely shut this skimmer weir. This stops any water from entering the skimmer. Note: Fits SP1091 Skimmer; Hayward New Style skimmer & weir. Weir Door Dimensions: 5-5/8" Width x 4-3/4" LengthReplacement Swimming Pool Skimmer Weir Door - 5 5/8 in. W, 4 3/4 in. L Item Number: 108529 In order to prevent any debris from escaping from the skimmer basket when your pump is turned off, there is a door that closes the skimmer system off. This door is called the skimmer weir. Without the weir, your skimmer won't skim the top of the water. Fits SP 1091 skimmer; Hayward NEW Style skimmer & weir. Like the skimmer, the skimmer weir adjusts to the water level in your pool on its own. It floats just on top of the water so that it can always collect floating dirt and materials. When you need to replace your skimmer basket or clean it out, you can completely shut this skimmer weir. This stops any water from entering the skimmer. Note: Fits SP1091 Skimmer; Hayward New Style skimmer & weir. Weir Door Dimensions: 5-5/8" Width x 4-3/4" Length