Offering a Used Rubber Gas Mask for Sale

I’m not certain whether trading goods is permitted on this forum, but I haven’t come across any rules that forbid it. A while ago, I purchased a grey rubber gas mask from eBay which I’ve decided to part with. My goal in selling it is to save up for an upgrade;). It’s crafted from light grey rubber and features glass lenses along with the usual attached tube. Additionally, I have a filter and a World War II era bag designed to keep the filter secure; since neither has ever been used, they didn’t catch my interest. Here’s the photo from the eBay listing where I originally bought it. Image I’m offering the mask for £15 with shipping included within the UK. I haven’t checked rates for international delivery yet, so if anyone is outside the country and interested, let me know and I’ll investigate the cost.