Flex Fletch LIT Lighted Nocks .166 Blue 3 pack 1006307. 166" inner diameter the Flex Fletch LIT Lighted Nocks offer enhanced visibility and performance for serious archers. These super bright blue lighted nocks feature an external on/off switch for tool-free use automatic activation upon shot release and can remain lit for up to 48 hours. With a lightweight design of just 16 grains these nocks help track arrows while preserving arrow integrity making them a smart and cost-effective solution for the range or the field. Specifications for Flex Fletch LIT Lighted Nocks: Manufacturer: Flex Fletch Color: Blue Additional Features: 0.166 Features of Flex Fletch LIT Lighted Nocks: Fits carbon shafts with 0.166" inner diameter Super bright blue light for high visibility External on/off switch requires no tools Auto-on activation when shot Up to 48 hours of continuous illumination Weight: 16 grains Includes 3 lighted nocks per pack Helps preserve arrows and reduce lost shots Package Contents: Flex Fletch LIT Lighted Nocks