bmd
Island in the stream.
Here's mine. They're a kind of spongey filter and a plastic cap. I can buy them right now but I don't wish to spend £16 on ten of each. I remember the red plastic caps of all different sizes from when I worked in a place that had new engines coming through it. They were used to keep dirt out of the ports during transit. They're 20mm diameter, which is exactly what I need. The sponge is just sponge but it's quite dense and can be whatever size as I can just cut it down.
