You will see the sleeves are a bit longer, which men often prefer for coverage.
3 PACK PROCLUB MENS COMFORT MUSCLE TEE PRO CLUB CASUAL SLEEVELESS SHIRT GYM
You will notice the small has a narrower shoulder seam for a better fit.
Olive Acid Wash Burnout T-shirts Adult S-3XL 60/40 Cotton/Polyester Blend
A nice touch in the Gildan model is the even stitching on the hem.
Premium Cotton T-Shirt Baseball Raglan Team Sport Jersey Tee 3/4 Sleeve Men’s
You will find the crew neck is just loose enough to let air circulate well.
Hanes Men’s X-Temp Comfort Cool Crewneck Undershirt (5 Pack)
Hanes t-shirts are a no-brainer when you need a quick gift for someone.