This 50" GB Titanium bar is a 153 drive link .063 3/8 bar for with the appropriate bar stud adapter to fit Husqvarna saws. This will fit Stihl 8800 saws without an adapter, and Husqvarna saws with the included adapter.  
 
Titanium® ProTOP™ Professional Chainsaw Bars
Features and Benefits:• One-piece Titanium alloy steel body• Laser-cut for precision shape and fit• Precision-ground grooves• Hardest wearing rails in the world• Increased flexibility in the bar body• Easy nose replacement• Nose side plates made of hardened Titanium alloy steel.• During hardening, the nose side plates are injected with Carbon Nitride, which guarantees that Pro-Top™ is the hardest-wearing replaceable sprocket nose in the world• Nose self-locks over a solid steel web on the bar body, held firmly together by three high-tensile rivets• Super-tough, high-tech alloy sprocket glides on precision Swiss bearings