FIREBOY-XINTEX Pneumatic flanged senders (PFS) are available for tanks without a threaded top port and utilize a five-bolt pattern for installation. 5-Hole FlangedGasket and five stainless steel 8# 32 mm Phillips screws are included No calibration or user programming required All senders are factory calibrated and ready to install However, PFS senders may be shortened and re-calibrated in the field to adapt to smaller tanks