40 pcs - 1/4". 40 pcs - 5/16". 40 pcs - 3/8”. 25 pcs - 7/16". 20 pcs - 1/2". Material: flexible and durable rubber, have good resistance capability to oil or water leak,UV light and ozone,phosphoric, hydrochloric, sulfuric,saltpeter acid and so on.
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