Ask 'Customer Service' at Harken what the difference actually is between the two - may be (as some parts are) the difference between delrin balls or 'torlon' balls in the bearings, they are sometimes interchangeable. GO In a message dated 9/4/2015 7:31:26 P.M. US Mountain Standard Time, griemmolo2@gmail.com writes: Wrinkle Boat Mates I am in the processing of researching a Harken Furler #434 Lo Load 500 lbs, @ $316 vs #435 Hi Load 950 lbs @ $365. Max wire size 1/8 inch on both Q 1. Is the Lo Load sufficient on a M15? Q 2. Is the extra $49 for a Hi Load worth it? George "We Can Not Control the Wind But We Can Adjust Our Sails"