Magnetometers are the most common instrument flown on NASA science missions and interference from onboard electronics requires that these instruments be deployed away from the spacecraft. Particle sensors and electric field sensors can have similar requirements creating a significant need for deployable booms. Currently, these booms are usually custom designed for each spacecraft, resulting in wasted development costs through repetition. The Composite Rolled Magnetometer and Instrument Boom (CROMIB) will be a highly capable, standardized boom for field instruments that can be scaled from 2m long to 12m long. CROMIB is a slit-tube rolled boom that will deploy using strain energy to simplify the storage canister and eliminate the motor and motor electronics. Rolling the boom provides a highly compact stowed volume. Recurring cost will be roughly 1/3 of the cost for custom designing a segmented deployable boom. CROMIB builds upon the composite boom experience gained from rolled solar arrays.