No one knows why. It will ruin his Special Day and he will always have parts left over. Good places to shop for men include Northwest Iron Works, Parr Lumber, Home Depot, John Deere, Valley RV Center, and Les Schwab Tire. It doesn't matter if he doesn't know what it is. Must be something I need.
Men enjoy danger.
Get him a monster barbecue with a 100-pound propane tank. Tell him the gas line leaks. Everyone knows why. Men love chainsaws. Never, ever, buy a man you love a chainsaw.