How to identify what keys you have, and what magnetikey blanks you need.

SC1 – Schlage Standard
SC1 is the most common Schlage residential keyway in North America. If your locks are Schlage brand (look for the "S" logo on the lock face), you almost certainly need SC1 blanks.
SC1 with Bottle Opener → SC1 without Bottle Opener → SC1 Lobe Profile →
SC4 – Schlage C Keyway
SC4 is another popular Schlage keyway, commonly found on commercial and multi-family Schlage locks. Check the key bow or the lock cylinder for the keyway designation.
SC4 with Bottle Opener → SC4 without Bottle Opener → SC4 Lobe Profile →
KW1 – Kwikset Standard (incl. Baldwin)
KW1 fits the vast majority of Kwikset locks and most Baldwin locks. If your deadbolt or knob has the Kwikset or Baldwin name, KW1 is your blank.
KW1 with Bottle Opener → KW1 without Bottle Opener → KW1 Lobe Profile →
M1 – Master Lock
M1 is the standard Master Lock keyway used on most padlocks and trigger locks with the Master brand. It's a distinctive profile — if your key has the Master Lock logo stamped on the bow, you need M1.
M1 with Bottle Opener → M1 without Bottle Opener → M1 Lobe Profile →
Y1 – Yale Standard
Y1 is the standard Yale keyway, common in apartment buildings and commercial properties using Yale brand cylinders. Yale locks often have a distinctive oval or round profile on the face of the cylinder.
Y1 with Bottle Opener → Y1 without Bottle Opener → Y1 Lobe Profile →
Still not sure? Use the free IdenKey app to photograph your key and identify the keyway instantly — then come back and shop your blank above.