SL-811: EasyEye Desk Lamp with Ionizer (uses 4-tube bulb) $72.00 SL-813: EasyEye Desk Lamp with Ionizer (uses 2-tube bulb) $72.00 SL-821: EasyEye Desk Lamp (uses 4-tube bulb) $64.00 SL-823: EasyEye Desk Lamp (uses 2-tube bulb) $64.00