Trijicon's Bright & Tough Night Sights feature a white ring around the glowing dots for daytime visibility, and for illumination in no light or low light conditions, a tritium-phosphor lamp protected within an aluminum sleeve and capped with a sapphire jewel to evenly distribute light and protect from solvents and puncture. They have a metal body with a silicone rubber cushion for shock protection to the tritium-filled glass lamps.
Specifications:

Type	Front/Rear Set
Frame Material	Metal
Frame Color	Black
Firearm Fit	Glock 17/19/20/21/22/23
Base Configuration
Style	3 Dot
Front Material	Tritium
Rear Material	Tritium
Front Color	Green w/White Outline
Rear Color	Green w/White Outline
Rail Size	N/A
Windage Adjustment	No
Elevation Adjustment	No
Fiber Diameter
Firearm Type	Pistol