sleeklighting - 13watt gu24 base 2 prong light bulbs- ul approved-120v 60hz - mini twist lock spiral -self ballasted cfl two pin fluorescent bulbs- 4200k 900lm cool white 4pack (60watt equivalent) - Walmart.com
Philips 18W 4 Pin G24q2 Very Warm White Double Twin Tube CFL Bulb | PL-C 18W/827/4P/ALTO (4 Pin) | Bulbs.com
Feit Electric 26-Watt Equivalent PL Vertical CFLNI 4-Pin Plug-in GX24Q-3 Base CFL Replacement LED Light Bulb, Cool White 4100K PL26E/V/841/LED - The Home Depot