B-Line Eaton series imperial cable tray and ladder, 6" Height, 24" Length, 18" Width, 18" and 12" Tray widths, Series 2-5 horizontal reducing tee, Alu

The Eaton B-Line 6A-18-12-HT12 horizontal tee joins an 18 inch wide tray to a 12 inch wide tray, so the reduction happens inside the fitting itself. Overall the fitting measures 18 inches wide by 24 inches long with a 6 inch side rail height. If both of your runs are the same width, this is the wrong fitting, you want a straight (non-reducing) horizontal tee.

It is a 12 inch radius fitting. The radius sets the minimum bend the cable takes through the branch, so check it against the manufacturer's minimum bending radius for the largest cable in the run. Pulling large power cable through too tight a turn is the usual cause of jacket damage at tees.

Aluminum. That keeps the fitting light for overhead work, 14.276 lb, and it is the usual choice where steel tray would corrode. It needs to match the rest of the run: mixing aluminum fittings into a steel tray system creates a dissimilar metal contact at the splice and the bolt patterns are not interchangeable across materials.

It carries CSA certification, which is what an inspector on a Canadian install will be looking for on the tray system.

The 6A-18-12-HT12 is supplied as the reducing tee fitting itself. Splice plates and the bolt hardware to tie it into the adjoining tray sections are ordered separately, along with the hangers or trapeze supports carrying the fitting. Plan on support near the fitting since a tee concentrates load at the branch.

No. This is a horizontal tee, it branches within the same horizontal plane. Taking a run up or down calls for a vertical elbow or a vertical tee instead.

14.276 lb for the fitting alone. Light enough for one electrician to set on a trapeze hanger, though the 24 inch length makes it awkward to hold one-handed at height.