Per Wikipedia:  The Mark 33 GFCS was a power-driven fire control director, less advanced than the Mark 37. The Mark 33 GFCS used a Mark 10 Rangekeeper, analog fire-control computer. The entire rangekeeper was mounted in an open director rather than in a separate plotting room as in the RN HACS, or the later Mark 37 GFCS, and this made it difficult to upgrade the Mark 33 GFCS.[19] It could compute firing solutions for targets moving at up to 320 knots, or 400 knots in a dive. Its installations started in the late 1930s on destroyers, cruisers and aircraft carriers with two Mark 33 directors mounted fore and aft of the island. They had no fire-control radar initially, and were aimed only by sight. After 1942, some of these directors were enclosed and had a Mark 4 fire-control radar added to the roof of the director, while others had a Mark 4 radar added over the open director. With the Mark 4 large aircraft at up to 40,000 yards could be targeted. It had less range against low-flying aircraft, and large surface ships had to be within 30,000 yards. With radar, targets could be seen and hit accurately at night, and through weather.[20] The Mark 33 and 37 systems used tachymetric target motion prediction.[19] The USN never considered the Mark 33 to be a satisfactory system, but wartime production problems, and the added weight and space requirements of the Mark 37 precluded phasing out the Mark 33.

Among ships to carry these open top Mk33 directors with the Mk4 radar, was USS Ranger, after 1942, and USS Enterprise (though her aft Mk 4 radar was mounted to the director differently than the directors in this set). 

The set includes two 3D printed open top MK33 directors, with the MK4 radars integrally printed on.  The parts are printed in a dark gray resin, and , overall, detail is good, though there are some print lines visible.  I especially like the wind deflectors around the rim of the open director and the arms that hold the Mk 4 radar.  The mesh on the radar screen is very fine.  Be careful you don't go to heavy when painting it, as you may clog it.  Below you can see photos of the director compared to Kraken's previously released closed top Mk33 director, and the Mk33 director included with the Trumpeter 1/350 USS Ranger. 

This is Kraken Hobbies 1/350 MK33 Gun Director, with MK4 Radar (Open Top).  It retails for $9.99 USD, and is available directly from Kraken Hobbies, who I'd like to thank for this review sample.   Recommended!