Jet Set Convertible Wristlet vs. Jet Set Smartphone Wristlet: what's the practical difference?

The Convertible Wristlet has a longer strap that converts from a wrist carry to a short shoulder clutch. The Smartphone Wristlet is a flatter, slimmer format sized primarily around the phone with minimal card storage. If you want flexibility between wrist and shoulder carry, go Convertible. If you just need a phone sleeve with a wrist loop, the Smartphone format is the more minimal choice.

Does the MK Signature Logo canvas hold up in India's humidity and monsoon?

The Signature Logo canvas is a coated jacquard base, not a raw canvas, which makes it reasonably humidity-resistant. The coated surface wipes clean with a dry cloth. The leather trim edges are more vulnerable in monsoon conditions; avoid prolonged rain exposure and condition the trim edges with a leather balm twice a year in coastal or high-humidity cities.

What fits inside the Jet Set Small Convertible Wristlet?

The Small Convertible Wristlet fits a standard smartphone up to 15 cm height, a slim folded wallet or a few flat cards, and a door key on a flat key ring. AirPods fit, a full key bunch does not. If you routinely carry more than phone plus two cards plus a key, size up to the Large Corner Zip Wristlet or a small crossbody.