The XS Standard Dot Night Sights are defensive tritium sights designed to enhance your Taurus 856 revolver with 24/7 self-illuminated visibility and proprietary photoluminescent Glow Dot technology.XS Standard Dot Night Sights for Taurus 856Self-illuminated tritium glows 24/7 for battery-free operationProprietary photoluminescent Glow Dot absorbs ambient lightConvex dots with increased surface area for enhanced light absorptionLarge highly visible design ideal for aging eyes or deteriorating visionEasy DIY installationPerfect for defensive applications and low-light shooting scenarios these night sights provide reliable visibility when you need it most combining tritium technology with innovative photoluminescent enhancement for superior performance.