VF401 - 

Honeywell VF401 Series
The VF401 is a high performance MR (magnetoresistive) sensor specially designed for sensing fine pitch ring magnets. It is a digital sensor in a miniature, flat, TO-92 style plastic package with a current output and 2 wire design. The VF401 bridge array is able to offer a reduced loss is sensor signal and accuracy and yet still be optimized to allow a greater air gap between the target and the sensor. It has a reduced sensitivity to run-out and is less sensitive to tilt tolerance accepting up to 10°, versus other typical ring magnets which can only accept up to 2° to 3° angle.