Here are some of the best Walther PDP light options for the 4.5" Compact & full size model.
All of them were thoroughly tested under normal usage conditions for an extended period of time, taking into account real-world usage scenarios and not on extreme stress tests that are unlikely to be encountered by most users.
Walther PDP Light Buying Guide
Disclosure: Red texts contain affiliate links for earning commission to support the website when you purchase
Surefire XH30 - Best Overall PDP Light

The Surefire XH30 is a high quality product for full size Walther PDP. This is pretty much an improved version of the X300U with added strobe mode for signaling and disorienting capabilities in tactical situations.
Multi-Lumen Modes - Choosing between 1,000 or 300 lumens. 1000 Lumens for target ID and threat control. 300 lumen for close proximity search without blinding the eye.

Works With DG Switch - Operate the switches with the Surefire DG switch
- Constant on/off
- Momentary on
Strobe Mode Added - Disorient opponents in tactical situations. Strobe on 300 or 1000 lumens based on mode setting

Hot Spot - Use it to temporarily impairing an adversary’s vision while keeping a safe distance.
Features:
- 1000 Lumens
- 11300 Candela
- 2 CR123A Batteries
- 4.8 oz
- 3.7 in
- IPX7
See detailed XH30 reviews here
Pros
- Bright lumen intensity
- Field grade durability
- Balanced throw and spill
- Strobe mode added
Cons
- No significant candela improvement from the X300U design
Streamlight TLR 1 HL - Best Duty Grade

The Streamlight TLR 1 HL ranks as a top choice for the Walther PDP when it comes to price and ergonomics.
Single Hand Operation - Toggle the switches using only one hand without hard press to activate the light or strobe
