This is a 25 watt ultraviolet bulb for the Matrix II fly trap.
Each Matrix ultraviolet trap uses 1 to 4 bulbs per trap.
Ultraviolet bulbs need replacing about every 12 months. Old bulbs may look the same to human eyes but the UV wave length that attracts flies and other flying insects will waver and fade as bulb ages.
Matrix Ultraviolet fly trap is unique in design that allows the use of 1, 2, 3 or 4 bulbs without harming the fly trap's power supply. By using 1 or 2 bulbs, you save on energy costs and can also place fly trap in smaller areas, when needed. For maximum power in large areas (at peak of fly season) use 4 uv bulbs in Matrix trap.