Tricorder

The tricorder is designed as a portable sensing, data analysis, and data communications device, with many specialized abilities which make it an asset to crews aboard starships and space stations as well as on away missions. On the Heisenberg, three models are made available, with mission-specific adaptations for two of them.

Starfleet Corps of Engineers R&D TR-1400 (Wrist Tricorder Mark I)
The TR-1400 Wrist Tricorder I is a vast step up from previous personal sensor designs. Constructed of translucent materials (primarily isolinear dicarbon ($$\overset{2}{C}$$)), the wrist tricorder is an amazingly sensitive first-, second-, and third-stage scanning and analysis computer. Powered by a slender sarium-krellide cell (the white wedge in the image) capable of operating the tricorder and its user's uniform for up to four weeks continuously between charges with minimal load. Charging can be accomplished inductively from any capable surface. At its lowest-power state, the tricorder simply displays the current time. When under use, the surface of the smooth band is a capacitive touch display. For larger control surfaces, the system's holographic emitter is capable of displaying a volumetric resistive keyboard and display. The wrist tricorder can also connect to a phaser's targeting and power systems to give the user such information as charge remaining and targeting data. While the TR-1400 is an excellent scanning system for general-purpose duty, it is not infinitely flexible. For mission-specific roles, the device must be coupled with a larger sensor unit. When attached to a user's wrist, the TR-1400 conforms to the contour of the user's arm, thinning or widening to accommodate its extra mass. It has user-configurable crystal coloration and control schemes, as well as interface colors. If rendered inert, the tricorder itself becomes a smoky gray color and physically releases the coupler keeping it around the user's wrist.

Starfleet Corps of Engineers TR-590 (Tricorder Mark X)
For durability and utility, nothing beats the Starfleet standby for decades, the TR-590 Tricorder X. Made of micro-milled, hull-grade duranium foam, the TR-590/X is able to withstand a direct concentrated blast of nadions for up to twelve seconds before being damaged to the point of uselessness. It was originally designed as a portable sensory, analysis, recording, and communications unit for use in field situations. While it still performs all of these functions, the TR-590 has been relegated to a backup role: It now acts primarily as a mission-specific sensor cluster for the TR-1400 Wrist Tricorder I. However, given that the little device is capable of much more delicate observations than its attached wrist unit, it is fairly rare that you will see engineering, scientific, or medical personnel without their own specialized TR-590.

Starfleet Corps of Engineers TR-600 (Tricorder Mark XI)
When the TR-590 Tricorder X isn't sensitive enough, Starfleet relies on the newer but less durable TR-600 Tricorder XI. This is a more streamlined, slimmer version of the device. Shaped more like a PADD than a traditional tricorder, the TR-600 comes standard with built in Scientific, Engineering and Medical scanners and software suites. These features are far more sensitive than the TR-590 and therefore have greater range and sensitivity. Unlike the previous model's method of adding hardware components to specialize, the TR-600 can be reconfigured to a far greater degree by simple swap-out of its software modules. Various service branches of Starfleet use the device, each with their own configuration.

The Marine Corps' variation of the TR-600 is invaluable for software intrusion activities, as it features more robust decryption and deciphering tools, at the expense of the entire Science  suite. These modifications make the tool an invaluable portable hacking device.

The Navy most commonly deploys the TR-600 to personnel aboard ships with an enlarged Engineering and Science toolkit and diminished Medical capacities, so as to be able to use the device to temporarily assume command over damaged or inactive console functions.

The Aerospace Forces carry a TR-600 entirely geared for Medical and Engineering tasks aboard each of their small-scale spacecraft as part of the ship's emergency kit.