Section 890.3500 - External assembled lower limb prosthesis(a)Identification. An external assembled lower limb prosthesis is a device that is intended for medical purposes and is a preassembled external artificial limb for the lower extremity. Examples of external assembled lower limb prostheses are the following: Knee/shank/ankle/foot assembly and thigh/knee/shank/ankle/foot assembly.(b)Classification. Class II (special controls). The device is exempt from the premarket notification procedures in subpart E of part 807 of this chapter subject to § 890.9 .48 FR 53047, Nov. 23, 1983, as amended at 63 FR 59231, Nov. 3, 1998