20W LED Fiber Optic O-Ring Light Microscope Illuminator – Microscope Central
GITD O-Ring Seals – JLHawaii808
LED O-Ring Lamp with Scissor Arm for Amazing Mobile Phone Camera Photography FP12-26 – My Tech Shoppe
LED Light Parts | Rubber O-Ring | Oznium
Internal O-Ring for PV End Plug to Product Water Tube of Housing - PV-OR40-210 | WaterAnywhere
MECCANIXITY Indicator LED Light 12V 16mm M16 Panel Mount Metal Waterproof Signal Lamp with O Ring for Machinery and Equipment, Blue Green Red White Yellow 1 Set: Amazon.com: Industrial & Scientific
O-Ring for PC-Series Flashlight
64 LED Ring Light, Variable Intensity by Section
GE 3-5/16 in. O-Ring ws03x10038 - The Home Depot
LED KIT REV8-RGB | Wet Sounds 8" RGB LED Ring Kit
Microscope Ring Light
GITD Glow O-Ring Seals For LED Flashlight | eBay
GITD O-Ring Seals – JLHawaii808
H8 H11 Headlight Bulb Replacement O-ring Set of 2 Fixes Loose Headlight Bulbs | eBay
LED Ring Light - 76mm Diameter : ID 4433 : $17.95 : Adafruit Industries, Unique & fun DIY electronics and kits