The Nash Siren Night Glo Small Bobbins are the visual indicators from Nash designed to complement the performance of the Siren R4 alarms. They connect via an MMCX bayonet push and twist fitting, drawing an LED output from the alarm. When the R4's Night Glo function is enabled, the bobbin produces a unique pulsing illumination that mirrors the alarm's LED. - Enlarged ball clip attachment for free line movement - Secondary grip clip attachment for slack lining - Flexible rubberised 10cm cable - Full range of matching coloured heads with pulsing glow that replicate R4 LED colours, plus a black head option with white LED - Small Bobbin weight 8gr - Large Bobbin weight 15gr - Both Bobbin sizes supplied with 2 x 5gr additional drag weights