The Fluted Rotor Core is an Epic Topside Material in ARC Raiders, used as a component when making amplified weapons. On Frozen Trail, find it at Pendola Pass inside the sealed, round wall hatches built into the exterior hull of a high ledge above the snowy valley. You need to pry these containers open; they do not open normally.
Quick answer: Breach the circular wall hatches along the exterior ledge above the snowy mountain pass. One of these hatches holds a Fluted Rotor Core alongside ARC Flex Rubber.
What the Fluted Rotor Core is
The Fluted Rotor Core is an Epic-rarity item in the Topside Material category. At 0.5 weight, it stacks to 3 units, keeping a full stack’s space cost low. Its concise in-game description identifies it as a component for producing amplified weapons, placing it with the other high-end materials used in the amplified weapon path.
Because it is Epic and tied to weapon amplification, it is worth protecting the moment you pick one up. In the footage, the player slots the core straight into the Safe Pocket, which keeps the item even if you go down before extracting.
Where it appears on Pendola Pass
Pendola Pass is the frozen summit map centered on the Cielo Sereno Observatory, unlocked after completing 25 rounds. It introduces the Flash Freeze hazard and a collapsed Emperor walker, and it is reached by Ballistic Gondola rather than the usual Tube network.
The core itself turns up in the breachable circular hatches built into an exterior ledge structure overlooking the valley. These are not standard containers. Each hatch is a round, sealed door that you force open with a pry bar using the BREACH & SEARCH prompt, which exposes the storage inside.
Climbing onto the upper ledge puts you alongside a row of these hatches on a narrow curved walkway. The first hatch in the sequence held an ARC Data Module and an Advanced ARC Powercell.
Following the walkway further along leads to a second sealed hatch. This is the one that matters for the core.
Breaching the second hatch reveals a Fluted Rotor Core sitting beside ARC Flex Rubber. Pull the core out and, given its rarity, drop it into the Safe Pocket right away.
You know the pickup worked when the core appears in your Safe Pocket slot and the ping callout confirms the Fluted Rotor Core is in your inventory.
What was in the hatches
The two breached hatches carried four materials between them. Here are the records for the items pulled from this ledge, with their category, rarity and weight.
| Item | Category | Rarity | Weight |
|---|---|---|---|
 Fluted Rotor Core | Topside Material | Epic | 0.5 |
 ARC Flex Rubber | Recyclable | Rare | 1 |
 ARC Data Module | Research Item | Epic | 1.0 |
 Advanced ARC Powercell | Topside Material | Rare | 1.5 |
The Fluted Rotor Core is the key pickup for crafting amplified weapons, but collect the other nearby items too. Some ARC enemies drop the valuable Advanced ARC Powercell, which is used to make the Surge Shield Recharger, Jolt Mine Blueprint, Tactical Mk. 1 (Defensive) Blueprint, and Energy Clip.
ARC Flex Rubber, the core’s shelf-mate
ARC Flex Rubber shares the second hatch with the core. It is a Rare recyclable that weighs 1 and can be broken down into crafting materials. On the crafting side, it goes into the Vertical Grip II, Angled Grip II and Stable Stock II blueprints, so it is useful to hang onto rather than leave behind.
Those three underbarrel and stock mods it crafts are solid recoil-control upgrades. Vertical Grip II cuts vertical recoil by 30 percent, Angled Grip II cuts horizontal recoil by 30 percent, and Stable Stock II improves dispersion and recoil recovery time, which makes the rubber a practical companion drop to the core.
