The ZPT-CP or ZOIC Chicago is the perfect air scribe for fossil preparation workshops. It is exceptionally suited to prepping most British fossils and many others worldwide. Engineered for dependability, versatility and power, the ZOIC Chicago air pen is an asset to any set up and an excellent all-rounder.

  • Powerful yet lightweight and comfortable
  • Available with chisel or pointed stylus
  • A fantastic all-rounder

  • Modified CP-9361 Air Scribe

  • Extremely frugal air consumption (5lpm)

  • UK Modified in our workshop

  • Guaranteed safe checkout

ZPT-cp the zoic chicago

The ZPT-CP or ZOIC Chicago is the perfect air scribe for fossil preparation workshops. It is exceptionally suited to prepping most British fossils and many others worldwide. Engineered for dependability, versatility and power, the ZOIC Chicago air pen is an asset to any set up and an excellent all-rounder.

Weight: 140g (5 oz)

Dimensions: 150mm length, 18mm diameter (5.9" long, 0.7" diameter)

Optimal Working Pressure: 6 Bars (90 PSI)

Air Consumption: 6 lpm (0.2 CFM)

Noise: 73 dB

Connection: 2.4m hose + Quick connector as required

On/Off Mechanism: Twist Valve

The ZOIC Chicago is our modified version of the original Chicago Pneumatic CP-9361; which has been the workhorse of the fossil preparation world for donkeys years due to its versatility, power and durability. We have modified it specifically for fossil preparation.

New Feature for 2021! The ZOIC Chicago is now fitted with our unique positive stylus locking mechanism, which means that when fitted with a chisel it will never rotate or spin when you’re working – not once, not ever. Easily switch between point and chisel.

fossil preparation air scribe tt me9100 cp9361 air pen fossil prep
  • Excellent all-rounder

  • ZOIC PalaeoTech PRO Range

  • A variety of stone-grade tungsten carbide styli to choose from. Starter kits come with the 2.5mm pointed stylus.

  • Very frugal air consumption 

  • Hardened stylus bushing for extreme durability in fossil preparation
  • Rubber coated for thermal insulation and vibration dampening
  • Air channels engineered to minimise noise output, whilst providing full frontal exhaust
  • Authentic CP-9361 parts used

The ZOIC Chicago is an excellent all-rounder. Before the days of modern, purpose-built fossil preparation tools, the base model, the Chicago Pneumatic (CP-9361) was the workhorse of many established workshops, universities and museums. The ZOIC Chicago is a modification of the CP-9361, designed specifically for fossil preparation, with a hardened bushing and a variety of tungsten carbide styli to choose from:

  • 2.5mm point - Robust and suited to matrix removal particularly on harder rocks

  • 2.5mm chisel - Great for matrix removal, shaping and smoothing

  • 2.0 mm point - Suited to a greater degree of precision and finishing work

  • We are also happy to accommodate requests for geometries, shapes or lengths of stylus that are not otherwise listed. Please contact us to discuss you requirements. 

Our Modifications

Variants of the CP-9361 have long been used on hard matrices due to their impact-driven internal mechanism, and are found in just about every professional prep lab in the world. The impact-driven internal mechanisms (piston/cylinder combination - more details here) give the tool power, whilst the size allows for controlled detail work. Chicago Pneumatic boast the highest durability on the market for the internals of this particular model. We’ve stripped the CP-9361 of any features that are not suited or durable in fossil preparation, and replaced them with our tried and tested ZOIC PalaeoTech features.

Our modifications are optimal for fossil preparation, and will withstand the test of time. Our stylus bushing is designed for minimal noise levels, whilst allowing a frontal exhaust that clears what you’re working from of dust and chips as you go. The stylus bushing is hardened and tempered so that you won't experience any stylus ‘wobble’, even if you use side-to-side motions when working.

We have also given the tool a rubber coating to minimise vibrations, provide more grip and provide some kind of insulation against the cold air flowing through (a nice touch considering so much fossil preparation takes place in unheated garden sheds!).

Technical Specifications

The air consumption (amount of air the tool requires to run) is about as low as it gets for a fossil preparation tool at only 6lpm (0.2cfm), providing 13,500 bpm at 6 Bars (90 PSI). The ZOIC Chicago has a nominal and maximum operating pressure of 6 Bars (90 PSI). A low air consumption means that your compressor will kick in less often creating less noise and costing you less to run. Low air consumption is also a great indicator of quality in air tools – the engineering in this tool is exceptional.

What’s in the box? The ZOIC Chicago air pen, fitted with 2.4m reinforced rubber air hose and particulate filter. Packaged in a wooden presentation box with a connector (as per user requirements), spare o-rings, silicone o-ring grease, Air Tool Oil, Manufacturer’s User Manual & Declaration of Conformity, Supplementary ZOIC PalaeoTech User Manual.

Already have a Chicago Pneumatic CP-9361? Want to turn it into a ZOIC Chicago?

We offer a ‘modification kit’, which will turn your existing Chicago Pneumatic 9361 into a ZOIC Chicago and open up a whole range of prep possibilities for you. Click here for product listing.

I already have a ZOIC Chicago? Can I put a chisel in it?

Please note that if you have purchased a ZOIC Chicago before these latest modifications, do not worry! We understand that these are big changes and we will retrofit your ZOIC Chicago free of charge to accept the new stylus options. When you buy from us, we want you to know that you will always have the best service we can give you, and this is no exception. Please contact us if you would like your ZOIC Chicago purchased before January 2021 to be retrofitted and you have not received an email with further information.


We manufacture each tool right here in Dorset, and take enormous pride in our workmanship. Each tool is quality controlled before it leaves our workshop. We use the genuine article as our starting point, sourced from Chicago Pneumatic, which means that the internals are exceptionally durable. Dependability, reliability, innovation and function are at the heart of what we do. We want for our tools to see you through whatever you may throw at them, and for you to enjoy using them. We want them to be as quiet as they can be, comfortable and a genuine pleasure to use. We design our tools to be low maintenance, requiring very little user input. If you look after your tools, they will look after you! 

How does the ZOIC Chicago compare to other tools?

The ZOIC Chicago is similar in terms of power and function to pens produced by other manufacturers such as the TT or the ME-9100, which are also both based to varying extents on the CP-9361.

The ZOIC PalaeoTech modifications are optimal for fossil preparation, designed for maximum power output, maximum tool lifespan, low noise, exceptionally low air consumption, frontal exhaust and ergonomic use. Our new positive stylus locking mechanism is unique, meaning that your chisel will never rotate when in use and does not rely on friction to hold the chisel in place. Even after many years of rigorous use and changing your stylus often, you will find that your hardened stylus bushing barely has any wear, and you won’t ever experience stylus wobble with ZOIC PalaeoTech tools allowing you to maintain ultimate precision. Learn more about how to choose an air pen and how the ZOIC Chicago fits in with the other ZOIC PalaeoTech tools here.

Warranty: 12 month warranty to cover manufacturing faults and defects. 

CE & UKCA Conformable

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