... used in switch buttons.It has many diameter specification:Φ4mm,Φ5.5mm,Φ6mm,Φ7mm,Φ8mm,Φ9mm,Φ10mm,Φ18mm,Φ19mm.ect. ... ok. LED indicator lightItemColorAC/DC Φ4 R/YG/Y/G/B/WAC/DC Φ5.5 R/YG/Y/GB/WAC/DC Φ6 R/YG/Y ... /GB/WAC/DC Φ7 R/YG/Y ... YG/Y/GB/WAC/DC Φ10 R/YG/Y/GB/WAC/DC Φ13 R/YG/Y/GB/WAC/DC Φ16 R/YG/ ... Y/GB/WAC/DC Φ18 R/YG/ ...