Single-ring, 14mm flashtube UV-coated and daylight-balanced at 5600K 250,000+ flash typical lifespan Lifespan dependent upon proper handling, power levels and frequency of use Flashtube for the following units: LINK, DigiBee (DB400 / DB800), AlienBees (B400 / B800 / B1600), White Lighting (X800 / X1600), UltraZap, and Zap 1000 flash units. All Paul C. Buff flashtubes are user-replaceable and arrive with instructions for replacement.