Genuine Unistrut P1834A-EG Channel Trolley Track Hanger / Joiner Support Bracket for All 1-5/8" Strut Channel CHANNEL TROLLY TRACK HANGER - Joiner support bracket. REQUIREMENTS - 3/8" x 2-1/2" bolt and 3/8" nut - NOT included. FOR USE WITH - All 1-5/8 series strut channels. SILVER FINISH - Silver Finish: Electro-Galvanized Zinc; ASTM B633, Type III. DIMENSIONS - 3.8 x 3.4 x 2.2 inches.