Nine pounds, and that is the whole reason this saw costs $730. The 540 XP Mark III is a professional rear-handle built around a 39.1cc engine and a narrow-kerf .325 mini / .043 chain, which is a combination aimed at crews doing high-volume limbing, brushing and small-diameter work where the saw is carried far more than it is cutting. Against the 445S it makes less power for $280 more, and that comparison is only sensible if weight and all-day vibration genuinely decide the job. Husqvarna rates it to a 16-inch bar, and 16 inches is an honest ceiling rather than an optimistic one at this displacement. The narrow .043 chain cuts fast in small wood but costs more and is harder to find than standard .050 stock — the 3/8 mini / .050 build is the option to specify if availability matters more than speed.

Best for: Crews doing all-day limbing, brushing and small-diameter cutting who need the lightest pro rear-handle Husqvarna builds.

Specifications

Engine class: 30cc class (by displacement)
Engine: 39.1 cc
Rated power: 1.9 kW
Bar length: 14 in
Bar range: 12-16 in
Single-pass cut: about 12 in (bar minus 2)
Chain: .325" mini pitch / .043" gauge (X-Cut SP21G; 3/8" mini / .050" S93G option)
Weight: 9 lb, powerhead only (excl. cutting equipment)
Power type: Gas
Use case: Professional
Warranty: 2-year consumer / 1-year commercial (Husqvarna limited)
Model: 540 XP Mark III

Manufacturer figures except the engine class and single-pass cut, which are derived here. What each spec means

9 lb pro rear-handle
Narrow-kerf .043 chain
39.1cc, 16-in max bar

Where it is strong

9 lb powerhead — three quarters of a pound under the 440 and the lightest pro rear-handle in the range
Narrow-kerf .325 mini / .043 chain cuts small wood noticeably faster than standard .050 stock
Pro-grade anti-vibe and magnesium construction in a saw sized for a full day of carrying
Rated to 16 inches, which is realistic rather than aspirational for 39.1cc
Alternative 3/8 mini / .050 build available when chain availability matters more than kerf