This is a Lowel Rifa-Lite EX55 Softbox Light. This softbox opens like an umbrella, and its removable front diffuser measures 21 x 21″ (53 x 53 cm).

Technical Specs:

Bulb Type: 1 x G9.5
Max Bulb Wattage: 500W
AC Input Power: 120 to 240 VAC, 50 / 60 Hz
Mounting: 5/8″ Receiver (via Fixture)
Cable Length: 4′ / 1.2 m
Dimensions: 24″ / 61 cm (Closed) // 21 x 21″ / 53 x 53 cm (Open)
Weight: 2.5 lb / 1.1 kg