Air filter Replaces OEM number:

Replacement air filter for Husqvarna Trimmer models 123, 223, 322, 323, 325, 326.
Replaces OEM: 537 18 63-01 537186301；5371863-01, 5038881-01;537 1863-01
HUSQVARNA 503 88 81-01, 537 18 63-01, 503888101, 537186301