User Guide Head BIS L-304-S115 Edition 0608 not flush mounting General installation notes for BIS L All read/write distances presume ambient temperature +20°C If BIS L components cre mounted in or on steel , or there is metal within the active field of the read/write head , the field dot will be reduced and communication may be compromised. When Installing date carriers on or in steel , note the reduced read/write distances. Precise distance data available on request.