They have unusual batteries and they build battery packs for replacement of your non working rechargeable batteries. My issue is that even though they build custom battery packs based on your needs and what you bring them for old battery packs. They are not cheap, and expensive compared to Amazon battery packs. I did get a new home security system replacement backup battery and it works great, they also take your old batteries to recycle them.
One of the best places to get batteries and reasonable prices. Always have stock and they’re new (not paying for a year-old battery like at the big box stores). Highly recommend.