My son is currently somewhere between medium and large so we usually take the large and it's often baggy for him.
These (big ones) were very tight for him. Go at least one size bigger! Otherwise they appear to be reasonably well made and are likely to be comfortable.
👕 Brix Boys Long Sleeve Tees - Optimized Clothing for Boys
42 Review
👦 ViCherub Boys' Black Large Underwear - Pack of 3 | Boys' Clothing Collection
42 Review
Comfortable & Practical City Threads Underwear: Sensitive-Friendly Boys' Clothing
47 Review
👕 Russell Athletic FreshForce Protection: Boost Your Boys' Performance with Assorted Clothing
49 Review
👕 Bold Pack Sleeve Active Hoodie Sweatshirt Set for Boys' Clothing - Stylish and Comfortable!
47 Review
🔥 Stay Warm and Active with Rocky Fleece Thermal Underwear Bottoms for Boys
44 Review
Arctix Youth Pants Reinforced: Large Boys' Clothing for Active Adventures
46 Review
🍉 Fruit of the Loom 6 Pair Cushion Ankle Boys' Clothing: Comfy and Stylish Selection for Active Boys
57 Review