7120 CEILING FAN JOIST BOX, PLAS | Round polycarbonate, 4 in Dia, 12.5 cu-in black non-metallic ceiling fan support saddle box, used in new work to mount a ceiling fan or heavy light fixture. Supports a 70 lb fan or 210 lb fixture. Saddle design straddles standard joist. Hands-free installation. 1/2 in setback. Two 1/2 in knock outs on the side. Four cable clamps, mounting hardware, instructions and high-strength, hardened screws included. 2 hrs fire rating, UL Orange Book. UL listed.