It depends on the model of the sound level meter.

Please buy a new one.
Ono Sokki's sound level meter provides a windscreen that varies in scale depending on the model number of the sound level meter as standard accessory.
（Diameter 70mm, or 90mm）
The windscreen has a special structure (continuous foam structure) so as to reduce the wind noise of the microphone when using outdoors and not to interfere with the measurement of the sound.
The characteristics of the sound level meter may be affected if you install a not genuine one or a product made by yourself.
Please be sure to use a genuine product.
If a windscreen is required, specify the scale (diameter) or the model name of the sound level meter (windscreen for LA- ××××).