
KeyGuard SL-500 Black
Score: 75/100
Master Lock 5422E
Score: 65/100Rankings

The KeyGuard SL-500 is a portable punch-button lock box with a spacious interior and alphanumeric keypad for flexible code creation. Its main limitation is a somewhat complex setup process requiring precise button rotation. It is ideal for realtors and property managers needing temporary, portable key access.

The Master Lock 5422E is a portable, push-button key lock box designed for quick, tool-free installation on door knobs. While it offers excellent usability with its touch interface and weather protection, it suffers from a critical security vulnerability where the lock can be decoded. It is best suited for low-risk, temporary access scenarios where convenience outweighs high-security needs.
| Attribute | ![]() | ![]() |
|---|---|---|
— | 5 keysbest | |
6.8 cm | 17.37 cmbest | |
2.1 cm | 8.08 cmbest | |
4 cm | 5.23 cmbest | |
| ↓ lower better | 0.45 kgbest | 0.84 kg |
— | 46.56 mmbest |
Click an attribute name to sort · Green = best, red = worst (relative to this comparison)
| Attribute | ![]() | ![]() |
|---|---|---|
Durability & Environment(1) | ||
Weather Resistance Rating | weather_resistant | Weather-resistant with cover |
Installation & Mounting(1) | ||
Mounting Type | shackle | Over-the-knob |
Storage & Capacity(1) | ||
Key Capacity (keys) | unlimited keys | 5 keys |
Design & Fit(3) | ||
External Height (cm) | 6.80 cm | 17.37 cm |
External Width (cm) | 2.10 cm | 8.08 cm |
External Depth (cm) | 4.00 cm | 5.23 cm |
Build & Design(2) | ||
Body Material | metal_plastic_coating | Metal |
Product Weight (kg) | 0.45 kg | 0.84 kg |
Security & Access(2) | ||
Lock Type | pushbutton | Alpha/numeric combination |
Shackle Length (mm) | unknown mm | 46.56 mm |


Products in the top-left offer the best value (high score, low price).

Professional reviewers praise the KeyGuard SL-500 for its superior storage capacity, intuitive phone-style keypad, and protective coating that prevents door scratches.
Demos simulate a positive user experience, noting the ease of fitting a handful of keys with space left over, but no recurring praise or complaints from actual buyers are documented.

Professional assessments highlight the product's ease of use and practicality for property management. However, a critical security review by the LockPickingLawyer revealed a significant vulnerability, demonstrating that the internal mechanism's simple sliding plate with notched rods can be decoded without tools.
Users generally provide positive feedback regarding the ease of use and practicality for property management. Common themes include appreciation for the straightforward operation in challenging conditions such as low light or when wearing gloves.
“very easy to use”

“a good amount of keys”


