here is a blue spot 110 dB alarm with a 120cm 10mm chain for security (motorcycle,etc). Alarm was tested with a calibrated device at 117dB(I worked in a noisy environment where testing was mandatory) in 2018. (curiosity). I believe the chain is Oxford but I can't find branding so is sold as unbranded. Obvious age and wear but has never been attacked and is fully functional. New batteries fitted by me 05\03\2026.(6xag13), should be good for a few years. Turn the shackle one way to arm the unit, the other way to just use as padlock. A visible and audible deterrent to thiefs. Postage is high due to the weight.
eBay