Difference between M1 and S2. S2 can work with the wireless key. S2 work with sherlock own app, while M1 work with mihome app.
Please noted the key only for S2 , not for M1. The item "Xiaomi Sherlock Smart Lock M1 / S2 Mijia Door Lock Keyless Fingerprint Password" is in sale since Monday, September 3, 2018. This item is in the category "Home & Garden\Home Improvement\Building & Hardware\Doors & Door Hardware\Door Locks & Lock Mechanisms".The seller is "katzaqualityproducts" and is located in Mainland. This item can be shipped worldwide.