Check the listing for details. BowJax SlipJax String Silencer, 19 Grains, Black, 4 Pack. Condition: New with tags. Listed at 10.75 USD. BowJax SlipJax String Silencer, 19 Grains, Black, 4Pk. Slipjax String Silencers have NEW dimples to help retain the silencer in the string. They require a bow press, but minimal effort to install. They are durable enough for most compound bows today. Weighs 19 grains each. 4 per pack. Mfg Number: 1040WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.WARNING: This product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm. For more information, go to www.P65Warnings.ca.gov.