"MAST LIFTING FRAME ASSEMBLY FOR MS-20 STRUCTURE ONLY. USED FOR LOW IMPACT RESISTANCE STRUCTURES FOR LIGHTING SUPPORTS FOR AIRPORT APPROACH LIGHTING SYSTEMS,MODELS ALSF-2 AND MALSR. ASSEMBLY OVER-ALL DIM. 36-5/8 INCH LONG BY 18-13/16 INCH WIDE BY 37 INCH HIGH. TRIANGULAR SHAPED BASE,3 POINT MOUNTING,MAST SLEEVE WITH CLAMPTO SECURE MAST IN RAISED OR LOWERED POSITION. WINCH WITH CABLE HOOK-UP TO MAST TO RAISE OR LOWER THROUGH MAST SLEEVE. MATERIAL,GALVANIZED STEEL. PER FAA SPEC. FAA-E-2702."