Mini Ollo LED Step Light with Eyelid CCT in Copper Havit Lighting HV2891T-CP-12V

No, and that is by design. Havit's data sheet states that "Solid Brass and Solid Copper fittings will naturally tarnish". The face is solid copper with no protective coating over it, so outdoors it will darken and develop a patina — patchily to begin with, then more evenly. Nothing about that is a fault or a warranty matter. If a permanently bright metallic face is what you are after, the 316 stainless or powder-coated black version of the same fitting will hold its appearance far better.

Havit says so, and the reason is specific to this finish: "When installing copper fittings, gloves must be worn to avoid any oils transferring to fitting". Bare copper takes fingerprints from the natural oils on your skin and they show up as marks in the early patina, which is difficult to undo once the fitting is sealed into a wall. It costs nothing to handle it in clean gloves and it is the single easiest thing to get wrong on an otherwise straightforward install.

Two published figures, and which one applies depends on how you are mounting it. Ø38 mm without a canister, Ø46 mm with a canister. The canister is the sleeve set into concrete or masonry so the fitting drops into a finished hole; in timber or a stud wall you usually will not use one. The trim overlaps the aperture either way, so measure the fitting or canister in your hand rather than working back from the face you can see.

No. It is a 12 V DC constant-voltage fitting and needs a suitable 12 V DC constant-voltage LED driver. Havit's instructions state it in capitals — "DO NOT CONNECT LIGHT FITTING DIRECTLY TO 240V". There is also a distance condition that is easy to overlook: no more than 25 m between the fitting and its driver, or Havit voids the warranty. It is Protection Class 3, low voltage, and no earth is required. The work has to be done by a licensed electrician.

By which marked neutral tail you connect, when you install it. The 3000 K tail gives warm white and the 5500 K tail gives cool white; joining both tails together gives 4000 K. The tail you do not use has to be terminated so the fitting stays IP rated. Once the joins are soldered and sealed the setting is permanent — there is no switch and no remote on this model — so decide for the whole installation before the first fitting is wired.

No. Both of Havit's sheets give the installation type as "Wall - Recessed", and Havit's own page describes it as a recessed wall or step light. Nothing published for this model covers foot traffic, vehicle loads or being set into paving where water pools. Havit builds a Mini Ollo intended for that duty as a separate model, HV2892T, listed as a step or inground light — that is the one to look at if the fitting has to go into the ground.

Two answers, both kept to what is actually published. On siting: the salt-water rule in Havit's instructions for this fitting names "Aluminium and 304SS fittings" and sets them back 5 km from salt water. This one is neither — solid copper face, 316 stainless body — so that clause does not name it and we have not applied it to this product. Havit also publishes no coastal approval for it, so we are not claiming one either. On dimming: all three sources list it as dimmable and none of them names a protocol, a dimmer or a driver, so check the dimming specification of the 12 V driver you pair it with rather than assuming.