The LIT Lighted Arrow Nocks are perfect for easy arrow tracking, designed to fit most carbon shafts with an ID of 0.246″ (6.2mm). Featuring an external on/off switch that requires no tools, these nocks automatically light up when the arrow is shot, offering superior visibility day and night. The nocks are long-lasting, staying lit for up to 48 hours, making them a cost-effective solution to protect your arrows. Each pack includes three lighted nocks, weighing 25 grains each.