Bulborama Supra Life GU24 base Mini Spiral compact fluorescent bulbs feature two bayonets protruding from the base of the bulb. The GU24 bayonets insert into matching holes in a fixture's socket, then twist and lock into place. Supra Life GU24 spirals feature a Tri Phosphor bulb coating to maintain brightness and up to 12,000 hour life ratings, making energy efficient GU24 base spirals excellent incandescent replacement bulbs.