Blackburn SAC 500 R 400 TN AL STR REDUCING SPLICE A:400 B:400

It's a bare compression splice. The insulation material is listed as None, so the connection has to be insulated in the field with tape, heat shrink, or a cold shrink sleeve to whatever level the installation calls for. The body is tin-plated aluminum, so it handles aluminum and copper conductors without the galvanic problem you'd get from a bare aluminum barrel on copper.

Both ends are 400, per the product designation A:400 B:400. It's the reducing-style SAC 500 body configured with 400 kcmil ports on each side, so it joins two 400 kcmil conductors end to end. If you need to splice 400 to a different size, you need a different reducing configuration in the series, not this one.

The SAC 500 R 400 TN is manufactured to ANSI C119.4, the standard for connectors used with aluminum and copper conductors. If your drawing calls out C119.4 compression connectors, this one carries that designation. It's made in the United States, which matters on Buy American or federally funded work.

The barrel is 5-11/16 inches long, and you have to add clearance at both ends for the crimp head jaws plus whatever insulating tape or shrink sleeve you're applying over it. Two conductors enter, one per end. In a tight service entrance gutter, lay the splice out before you cut cable to length.

They do different jobs. This is a compression (crimp) splice, which needs a hydraulic or battery crimp tool with the correct die and gives you a permanent, non-reusable joint that stays tight without re-torquing. A mechanical set-screw splice installs with a hex key and can be taken apart, but it needs torque verification and is generally the choice when no crimp tool is on site. If the spec calls out ANSI C119.4 compression, a set-screw body is not a substitute.

The tin plating is what makes that possible. Blackburn's SAC series is an aluminum-bodied compression splice, and the tin-plated surface lets it be used on copper as well as aluminum, which is the point of the AL/CU-rated C119.4 connector. Use the die called out for the barrel and the conductor material you're actually crimping.

Sold each. Order one per splice point, and remember a three-phase run with a neutral needs four of them, plus insulating material for each joint since the body ships bare.