Key rings and holders, mostly for item trackers.
Belkin doesn't sell the Secure Holder with Key Ring for AirTag in Singapore, only the strap version. I ordered mine from Amazon.sg for S$23.52, shipped free from the US via Prime, arriving as a two-pack at about S$12 each.
If Apple's AirTag Leather Key Ring feels too pricey, OEM versions are cheap. I bought two from Shopee at S$3.32 each. The silicone holder comes in six colours, though the non-stainless metal ring will eventually rust.
The Apple AirTag Leather Key Ring retails for S$55, or S$49.22 on the EPP, in Baltic Blue, Saddle Brown, and Product Red. With a stainless steel ring and soft French leather holder, it feels premium, if pricey.