OATEY 43816 3 in. or 4 in. PVC 45° Closet Flange with Plastic Ring without Test Cap

Both. The Oatey 43816 fits over 3 inch PVC pipe or inside 4 inch PVC pipe, so one part covers the two common closet bend sizes. It is a solvent weld connection, so you are gluing it with PVC cement, not gasketing or clamping it.

A 45 degree flange is for openings where there isn't room to bring the drain up vertically under the toilet, typically a tight joist bay or a wall too close behind the bowl. The Oatey 43816 has a 45 degree bend with 360 degree rotation, so you can swing the inlet to whatever direction the pipe is coming from and still land the flange where the closet bolts need to be. If your closet bend already rises straight up into the floor, use a standard flat flange instead.

Yes. The Level Fit design lets the flange set flush, which is what keeps the toilet sitting level and the wax ring sealing correctly on an angled-inlet installation.

Plastic. The 43816 is all-plastic construction, ring included, so there is no steel or stainless ring to rust in a bathroom slab or a damp crawlspace. The tradeoff versus a metal-ring flange is that you are relying on plastic for the closet bolt slots, so don't overtighten the toilet nuts.

No test cap is included with the 43816. If your inspector wants the closet opening capped for the water or air test, order a cap separately or choose the test-cap version of the flange.

Yes, and the spacing is a code question. Oatey calls out checking local codes for proper piping support spacing on the 43816, because the 45 degree inlet puts the drain line on a run that needs hanging or blocking rather than resting on the flange itself.

The 43816 is listed at 0.85 lb with a volume of 0.117, light enough that a truck stock of several adds almost nothing to the van.