CZ has now discontinued this model - these are the last ones.
This is the CZ 3 round flush fit factory magazine for the CZ 527 M1 in .223 Remington, which has a different trigger guard from the CZ 527 American/Varmint/Carbine and other models.
This magazine will not work as a replacement for 5 round magazines - unless the trigger guard and magazine well is replaced with the flush fit M1 type.
Manufactured from blued steel, the single stack magazine features a stainless steel follower and heat treated spring.