B-Line Eaton series imperial cable tray and ladder, 4" Height, 84" Length, 30" Width, 30" and 12" Tray widths, Series 2-5 horizontal cross, Aluminum,

It joins a 30 inch wide run to 12 inch wide branches, so the four legs are not all the same width. The fitting is 30 inches wide overall and 84 inches in total length across the cross. If every leg on your intersection is 30 inches, this is the wrong part number, you need a cross where all four widths match.

33.85 lb bare. That is the fitting only, before cable fill, so add it to your trapeze or hanger load at the intersection. At 84 inches across and 30 inches wide it usually wants support on more than one leg rather than a single center hanger.

Use a horizontal cross when four tray legs meet at one point in the same plane, which is what the 4A-30-12-HX24 is made for. Two tees back to back leave a short straight section between them and add splice points; the cross is one piece with the 24 inch radius carried through every turn. Where only three legs meet, a tee is the correct fitting, not a cross.

Order Eaton B-Line part number 4A-30-12-HX24. The code reads as 4 inch aluminum rail, 30 inch main width, 12 inch branch width, horizontal cross, 24 inch radius, which is a quick way to confirm you have the right fitting against a drawing callout.

The 4A-30-12-HX24 is aluminum, which keeps a 30 inch wide cross down to 33.85 lb and resists corrosion without a coating, so it is the usual pick for exposed indoor plant, coastal, and wash-down areas. If the specification calls for hot-dip galvanized or stainless steel tray, this aluminum fitting will not match the run and you need the steel equivalent.