Part Number: 2053. Masimo 20-pin Red sensor is for use with Masimo monitors that require the Masimo Red sensors, such as Rad-57 and Radical-7 The adjustable hinge allows the sensor to be adjusted to various finger sizes. For short term or "spot check" monitoring. Recommended weight range: greater than 30kg. Recommended monitoring site: Ring or middle finger of non-dominant hand. Sensors must be repositioned every 4 hours.