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Theory X 170 FPV Kit, 4" Props



*at participating retailers

Theory X 170 FPV Kit, 4" Props

Item #: BLH9440


Retail: $69.99*

Find a Retailer Buy Now *Avaliable at participating retailers


Key Features

  • Composite airframe featuring a solid 4mm main plate provides exceptional durability while maintaining a lightweight profile
  • Exteme simplicity in design which not only keeps the airframe lightweight overall, it makes building a breeze
  • Multiple motor mounting holes to fit a variety of motors. 16-19mm motor mount support
  • The top stack includes convenient cut outs for a variety of video transmitters and cameras
  • The ingenious top stack was designed to hold a GoPro Hero 3 or 4 with a single strap allowing you to have a race airframe with the ability to run an HD camera
  • The simple FPV camera mount allows for angles up to 90 degrees allowing you to choose just how fast you want to go
  • The extremely tough bottom plate provides an XT60 connector cutout for mounting your battery lead to prevent prop strikes in air
  • The compact frame design is open enough to place electronics easily within a condensed profile
  • Specifically designed for 4” propellers and recommended 2300Kv to 2650Kv motors for optimal performance

Product Specifications

Gross Weight:
Flying 14.1-15.8oz (400-450g) Airframe 3.7oz (105g)
Rotor Blade Length:
5 inch maximum
Experience Level:
Is Assembly Required:


The Blade® Theory™ X Frame Kits are designed for durability, simplicity, and speed. Constructed exclusively for racing, the assembled kit containing composite plates, and all recommended equipment has a flying weight of only 400-450g. The airframe features multiple motor mounting holes to fit a variety of motors and the cover plate includes cutouts for a variety of connectors and video transmitter as well as the XT-60. The camera mount is highly adjustable and can angle from 45 to 90 degrees. Advanced FPV pilots and those experienced in building quadcopters from scratch, will appreciate the compact design featuring enough room for all electronics and a GoPro camera. Its true X design provides an excellent feel in the air with more agility, the opportunity to hit top speeds, and the ability to reach the finish line first.

Theory X 170 (4”) Advantages
The advantages to using a smaller, 4” propeller racer is agility. A smaller profile means you can turn and corner much faster around flags and gates in a race, a significant advantage over other sizes in a tighter, more technical race course.

Manuals and Support

Related Parts

Completion Guides Recommended  See All

  • 20A ESC BLHeli Opto Quad Pack[BLHA1006]

  • 2205-2650Kv FPV Racing Motor[BLHA1022]

  • 1300mAh 4S 14.8V 35C LiPo Battery Thrust[EFLRB13004S35]

  • SpiroNet 5.8GHz RHCP Ant Set (2pc)[IRLSN5G8RHSET]

Parts Listing  See All

  • Hardware Kit: Theory X[BLH9401]

  • FPV Standoffs, 35mm: Theory X[BLH9402]

  • FPV Battery Strap: Theory X[BLH9403]

  • []

Optional Accessories  See All

  • 20A ESC BLHeli Opto Quad Pack[BLHA1006]

  • 1000mAh 4S 14.8V 35C LiPo Battery Thrust[EFLRB10004S35]

  • 1300mAh 4S 14.8V 35C LiPo Battery Thrust[EFLRB13004S35]

  • SpiroNet 5.8GHz RHCP Ant Set (2pc)[IRLSN5G8RHSET]