Includes: This kit includes plastic washers, an O-ring, a guide cone, an E-clip, and a locking knob.CX900DA Knob Kit Replacement: The CX900DA knob kit is a replacement compatible with Star-Clear Plus Filters models C751, C900, and C1200.CX900G Locking Knob Replacement: The CX900G locking knob replacement kit is compatible with for Star Clear Plus Filter models C900, C9002, C1200, C12002, C12002S, and C751.Suitability Confirmation: Before purchasing, please that your model is suitable for this replacement knob kit.High-Quality Materials: Made from materials, this kit is designed to a secure and reliable connection for your pool filter.Product Name:CX900G Locking Knob and CX900DA Pool Filter Knob KitFitment:for Star-Clear Plus Filters (C751, C900, C1200, C9002, C12002, C12002S)Number of Pieces:Plastic Washers x 2, O-ring x 1, Guide Cone x 1, E-clip x 1, Locking Knob x 1Colour:BlackMaterial:PlasticPackage Contents:1 * washers kitOnly the above package content, other products are not included.Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.