Description
Cthulhu Spire MTL RBA
The Spire MTL RBA by Cthulhu has been designed with MTL vaping at the forefront. There aren’t many dedicated MTL rebuildables on the market – most are just all-rounders – but Cthulhu used computational fluid dynamics software for airflow optimisation, bringing you quiet and smooth bottom airflow. They’ve included four different airflow pins ranging from 1.0-1.8mm with two chimney options to really customise your draw and throat hit. The Cthulhu Spire MTL RBA is designed in a BORO configuration with the inclusion of the Cthulhu Boro Tank, so you can pair this with most BORO mods and AIO setups. With 3.5mm large head screws, the single coil deck allows for easy coil installs with that flavour-focused airflow system just beneath. Cthulhu are well known for their high-end rebuildable quality and flavour-focused RBAs, and the Spire MTL RBA is no exception.
Spire MTL RBA Key Features
- Boro Configuration
- Rebuildable Atomiser
- Includes Cthulhu Boro Tank
- MTL Vaping
- Quiet & Smooth
- Bottom Airflow
- 4 Pins: 1.0 / 1.2 / 1.4 / 1.8mm
- 3.5mm Large Head Screw
- Easy Single Coil Installation
- Flat & Dome Shaped Chimneys
- Designed to offer Different Throat Hits
- Made From 316SS
Boro Configuration with Included Tank
The Spire MTL RBA uses boro configuration, which means it fits most boro mods and AIO devices on the market. Cthulhu includes their own boro tank in the box so you can start vaping straight away. If you’ve already got a boro mod, just drop the Spire in and you’re sorted. The standardised boro sizing makes this RBA compatible across different setups without needing adapters or modifications.
MTL-Focused Bottom Airflow Design
Cthulhu used computational fluid dynamics software to design the Spire’s airflow system. What that means in practice is quiet, smooth airflow without the whistling you get from some bottom airflow RTAs. The airflow comes up from beneath the coil, hitting your build directly for focused flavour. Because it’s designed specifically for MTL rather than being adapted from an RDL system, the draw feels natural and controlled.
Four Airflow Pins and Two Chimney Options
You get four airflow pins in the box: 1.0mm, 1.2mm, 1.4mm, and 1.8mm. Swap them out to adjust how tight or loose your draw is. Smaller pins give you a cigarette-tight MTL inhale. Larger pins open things up slightly for a looser restricted draw. The Spire also includes two chimney options – flat and dome-shaped. The flat chimney gives a sharper throat hit. The dome shape smooths things out. Between the pins and chimneys, you can dial in exactly how you want your vape to feel.
Single Coil Deck with 3.5mm Screws
The deck uses a single coil configuration with large 3.5mm head screws. Installing coils is straightforward – the big screws are easy to grip and tighten without fiddling. Wicking is simple too, with clear channels showing you where the cotton needs to sit. Single coil setups use less power and less e-liquid than dual coil builds, which suits MTL vaping where you’re after flavour rather than clouds.
High-End Build Quality from Cthulhu
The Spire MTL RBA is made from 316 stainless steel. Cthulhu have a reputation for solid machining and quality control on their rebuildables. The threading is smooth, the parts fit together cleanly, and everything feels well-made rather than loose or cheap. If you’ve used Cthulhu RTAs before, you know what to expect – this RBA keeps up that standard.
Why Choose the Spire MTL RBA?
The Spire MTL RBA is built specifically for MTL vaping rather than trying to do everything. You get proper MTL airflow that’s been engineered with software rather than guessed at. Four airflow pins and two chimneys let you fine-tune your draw and throat hit. The boro configuration means it fits most AIO setups, and Cthulhu includes their own tank so you’re not hunting for compatible parts. Single coil building is straightforward with those large 3.5mm screws. If you want a dedicated MTL rebuildable with proper engineering behind it, the Spire delivers.
What’s in the Box?
- 1 x Cthulhu Spire MTL RBA
- 1 x Cthulhu Boro Tank
- 4 x Airflow Pins (1.0mm, 1.2mm, 1.4mm, 1.8mm)
- 1 x Flat Chimney
- 1 x Dome Chimney
- 1 x Spare Parts
- 1 x User Manual






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