Purpose of a non spring action, fixed height free motion foot is to hold the fabric flat at all times.
Does not allow the foot to hop up and down on the fabric which can cause catching fabric or thread skipping, shredding, and breakage. Purpose of a spring loaded free motion foot is to prevent needle deflection in fabric, holding the fabric down in place while needle is entering and exiting the fabric.
Brother "U" Embroidery / Presser Foot NV500D/NV1500D/NV2500D # XD0313051
I was pleased to find these parts and to get them quickly. Your price seemed fair. Thanks!