Pay in installments of $5.71 with
,
and
Shipping Estimate
USA
- USA
- CAN
- USA
- CAN
Ships within 48 hours · Estimated delivery Jul 2 - Jul 7
Promo Codes Available:
For Your Every Summer RSVP, with Code: SUMMER15
Description
gps tracker fahrrad amazon Gemstone Bike GPS TrackerGemstone Bike Subscription Free 4G GPS Tracker Protect your ride with the Gemstone Bike, a high performance 4G GPS tracker designed for eBikes, cargo bikes, e scooters, and strollers. Engineered by Copenhagen Trackers, this discreet device offers a security solution with NO monthly fees or hidden SIM subscription. Key Features Up to 6 Year Battery Life: Industry leading power allows for up to 6 years of tracking (at 1 position per day). No Monthly
Gemstone™ Bike | Subscription-Free 4G GPS Tracker
Protect your ride with the Gemstone™ Bike, a high performance 4G GPS tracker designed for eBikes, cargo bikes, e-scooters, and strollers. Engineered by Copenhagen Trackers, this discreet device offers a security solution with NO monthly fees or hidden SIM subscription.
Key Features
- Up to 6-Year Battery Life: Industry-leading power allows for up to 6 years of tracking (at 1 position per day).
- No Monthly Fees: Includes a free lifetime SIM card with global 4G/LTE-M coverage in over 150 countries.
- Tamper-Resistant Security: The lightweight, compact unit mounts securely to you frame using included safety screws to prevent theft and tampering.
- Indoor Tracking Possible: Pinpoint your bike outdoors via GPS, and with a Premium upgrade allow WiFi-positioning, helping you locate your eBike in basements.
-
Danish Engineering: Developed and assembled in Denmark, out trackers are IP68 waterproof and dust-proof, ensuring reliability in any weather.
Technical Specifications
- Connectivity: 4G LTE-M, NB-IoT, and 2G
- Size: 7.7 x 4.7 x 5.7 CM | Weight: 101 G.
- Coverage: 150+ countries
Stop worrying about bike theft and join over 100,000 customers who trust Copenhagen Trackers to keep their valuables safe.
Shipping Notes
- Free Standard Shipping on $100+ Orders to the USA.
- Except Preorder products are shipped in 48 hours.
- Delivery to the USA:
- Standard Shipping : 3-10 business days
- If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
- We offer a 30-day return/exchange service after receiving.
- Final sale items are not eligible for returns or exchanges.
- To process your return/exchange, please contact us at [email protected]
- Please click here for more details>>> Return & Exchange Policy
4.2 ★★★★★
Based on 969 reviews
Sort
Product Reviews
★★★★★ 4
Understanding AI prompts as a science
Format: Audiobook
Prompt engineering is the art and science of finding the right words to generate the right responses from artificial intelligence (AI). It's becoming a skill in-demand in today's workplaces. It's also becoming an essential skill for life. To understand prompt engineering, you must understand how AI tools understand their inputs. This book explains that to you in many forms.
It covers prompting as it intersects all the major AI disciplines, like general prompts (as in a ChatBot), fine-tuning, and retrieval-augmented generation (RAG). It also introduces how prompting intersects a couple of image-generation tools.
As a scientist, I appreciate the theoretical approach to these practical matters. Too many people are hacks at AI these days, and any technical understanding can rapidly advance an individual's effectiveness. Prompt engineering is often made fun of as a "soft" topic, but as this book demonstrates, it intersects all the major AI areas. Presumably less garbage in means less garbage out. This book shows how you can make that take place.
As typical for O'Reilly materials, this book appeals to people who desire an intermediate-to-advanced understanding of how AI works. It's not for the casual user. Anyone technical involved in professional knowledge generation using AI can benefit from understanding the dynamics "under the hood." It's a good, though perhaps not ground-breaking, textbook for those of us unable to take a class in the subject. Prompt engineering may be a soft topic to many, but books like this ground the field in the science that can make or break a digital or software product.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 13, 2025
★★★★★ 5
Great book
Format: Paperback
Great book! It is helpful as I work towards my Masters of Science in Applied Artificial Intelligence
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on December 20, 2025
★★★★★ 5
Comprehensive Guide with Practical Insights
Format: Paperback
This is a solid book for understanding the art and science of working with LLMs and other generative AI models. I always struggled with getting the output I was looking for, and wasn't sure how best to "ask" the models for what I wanted. This book did a great job of laying out the strategies and practical guidance to craft the prompts. There were a lot of tips and tricks, but the overall understanding and framework around prompt engineering has been super useful.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 25, 2024
★★★★★ 5
A must read!
Format: Paperback
Hands down, the best book on prompt engineering and implementing LLMs. Really enjoyed Michael and James deep dive. Whether you're technical or not, this book is foundational to a deeper understanding in how to properly explore and implement LLMs.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 25, 2024
★★★★★ 4
Helpful for GPT/LangChain framework
Format: Paperback
I applaud the authors for putting forth a comprehensive introduction in a rapidly evolving space. I absorbed a lot, helpful as I was developing a prototype — using open source methods.
And that’s where I was disappointed. The LLM and examples are highly adapted to OpenAI’s GPT-x and the bulky LangChain framework, something not obvious until you dig in to the book. Sure, this may be where newbie demand was when the authors began writing. But as the open source models and OpenAI alternatives gain speed (e.g. Llama 3.1, Groq, etc.) this book may quickly need an updated and expanded version to stay relevant.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on August 7, 2024