Bow Jax String Sleeve Silencers 16 grain 4 Pk Black. Eliminates the need for speed buttons. Silences while improving speed. Installs by slipping over the string(bow press required). Weigh 16 grains each. 4 per pack. Specifications for Bow Jax String Sleeve Silencers: Manufacturer: Bow Jax Quantity: 4 Weight: 16 grain Features of Bow Jax BowJax String Sleeve Silencers: Helps to eliminate string oscillation while improving speed Can be used with or without string silencers Weigh 16 grains each Package Contents: Bow Jax BowJax String Sleeve Silencers Bow Jax 1037black: String Sleeve Silencers 16 grain 4 Pk Black