Tokyo Marui MK23 with Socom silencer, green gas pistol. It's in use by member Headhunter.

Specifications

Adjustable hop-up.
Weight: 1kg.
Length: 427mm.
Capacity: 28 rounds.
Power: 350 fps.
Power source: Green gas.
No blowback.
Semi auto.

Accessoires

LAM unit.
Socom silencer.

Practise

How does this side arm work in the field?
This airsoft gun works on green gas, so you have to use the appropriate kind of gas under cold conditions. The main reason for this sidearm is for military simulation and sometimes for CQB (Close Quarter Battle) whereby you yell "Pang" when too close in range (mostly inside 5 meter distance). When you use a sniper rifle or DMR your are obligated to have a sidearm too in Holland.
A review (in Dutch) can be found here by member Headhunter.