Assuming you want a product review on the top 5 best hex key sets with extensions:

Introduction
A hex key set is an important tool for many do-it-yourselfers, as it allows you to loosen and tighten screws and bolts. There are many different types of hex key sets on the market, so it is important to choose the right one for your needs. In this article, we will take a look at the top five best hex key sets with extensions, and compare their prices and features.

Top 5
1. The first hex key set on our list is the Dewalt DWHT70265, which is a 12-piece set that includes a variety of sizes. The set is made of chrome vanadium steel for durability, and the keys are color-coded for easy identification. The set also comes with a storage case for easy organization. Price: $19.97.

2. The next hex key set on our list is the IRWIN Tools Hanson Metric Hex Key Set, which is a 9-piece set that includes metric sizes. The keys are made of heat-treated alloy steel for strength and durability, and the set comes with a storage pouch for easy organization. Price: $11.99.

3. The third hex key set on our list is the Stanley STHT71654, which is a 7-piece set that includes both metric and standard sizes. The keys are made of heat-treated carbon steel for strength and durability, and the set comes with a storage pouch for easy organization. Price: $9.97.

4. The fourth hex key set on our list is the Craftsman 9-31794, which is a 6-piece set that includes both metric and standard sizes. The keys are made of heat-treated alloy steel for strength and durability, and the set comes with a storage pouch for easy organization. Price: $9.99.

5. The fifth and final hex key set on our list is the Klein Tools 85074, which is a 4-piece set that includes metric sizes. The keys are made of nickel-plated steel for strength and durability, and the set comes with a storage pouch for easy organization. Price: $7.97.

Comparison
Now that we’ve taken a look at the top five hex key sets with extensions, let’s compare their prices and features.

The Dewalt DWHT70265 is the most expensive set on our list, but it is also the most comprehensive, with 12 pieces and a variety of sizes. The keys are made of chrome vanadium steel for durability, and the set comes with a storage case for easy organization.

The IRWIN Tools Hanson Metric Hex Key Set is the second most expensive set on our list, but it only includes 9 pieces. However, the keys are made of heat-treated alloy steel for strength and durability, and the set comes with a storage pouch for easy organization.

The Stanley STHT71654 is the third most expensive set on our list, but it only includes 7 pieces. However, the keys are made of heat-treated carbon steel for strength and durability, and the set comes with a storage pouch for easy organization.

The Craftsman 9-31794 is the fourth most expensive set on our list, but it only includes 6 pieces. However, the keys are made of heat-treated alloy steel for strength and durability, and the set comes with a storage pouch for easy organization.

The Klein Tools 85074 is the least expensive set on our list, but it only includes 4 pieces. However, the keys are made of nickel-plated steel for strength and durability, and the set comes with a storage pouch for easy organization.

Conclusion and Recommendation
Based on our comparison, we recommend the Dewalt DWHT70265 as the best hex key set with extension. It is the most expensive set on our list, but it is also the most comprehensive, with 12 pieces and a variety of sizes. The keys are made of chrome vanadium steel for durability, and the set comes with a storage case for easy organization.