[Replacement Part Number] Part Number: 311011. If your walk behind string mower is having trouble with its cutting performance or isn't running smoothly, it might be time to replace the trimmer mower parts. [Wide Compatibility] Compatible with following weed model series: for Trimmer, Fence Trimmer, T4X, TR Series, etc., 311011 trimmer mow ball replacement is suitable for a variety of and models of walk behind string mowers. [Strong Durability] The trimmer parts mow ball is made of plastic material with good impact resistance and weather resistance, suitable for use in various environments. [Warm Tips] Our mow ball head for walk behind string trimmer is precisely sized to a with the trimmer mowers walk behind. It is recommended to clean the installation area before installation to a secure installation. Please note:the physical slightly color difference or difference, does not affect the use, please do not mind, thank you! Color:As Shown Material:plastic Package Contents: 2 * trimmer mower mow balls Only 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.