This is the Retract Set for use with the Top-Flite P-51D, P-47 and AT-6 ARFs. FEATURES: Nylon and metal construction Black in color Mechanical type retract units INCLUDES: Two Retract Units REQUIRES: Struts- AT-6: TOPA1748 P-51: TOPA1735 P-47: TOPA1789 SPECS: Length: 1.75" (44mm) Width: 1.75" (44mm) Height: 1.12" (28.4mm) JiM 11.17.08 ir/jxs updt lmm 02.10.10