--- product_id: 788762167 title: "Rocky Thermal Underwear for Boys Cotton Knit Thermals Kids Base Layer Long John Pajamas Set" brand: "rocky" price: "¥10773" currency: JPY in_stock: true reviews_count: 5 category: "Rocky" url: https://www.desertcart.jp/products/788762167-rocky-thermal-underwear-for-boys-cotton-knit-thermals-kids-base store_origin: JP region: Japan --- # Moisture-wicking microfibers Thermal knit retains body heat 55% Cotton & 45% Polyester blend Rocky Thermal Underwear for Boys Cotton Knit Thermals Kids Base Layer Long John Pajamas Set **Brand:** rocky **Price:** ¥10773 **Availability:** ✅ In Stock ## Summary > ❄️ Keep the chill out and the fun in with Rocky Thermals! ## Quick Answers - **What is this?** Rocky Thermal Underwear for Boys Cotton Knit Thermals Kids Base Layer Long John Pajamas Set by rocky - **How much does it cost?** ¥10773 with free shipping - **Is it available?** Yes, in stock and ready to ship - **Where can I buy it?** [www.desertcart.jp](https://www.desertcart.jp/products/788762167-rocky-thermal-underwear-for-boys-cotton-knit-thermals-kids-base) ## Best For - rocky enthusiasts ## Why This Product - Trusted rocky brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Versatile Base Layer:** Ideal for outdoor sports, lounging, or cozy sleepwear in cold climates - • **Stay Dry, Stay Active:** Advanced moisture-wicking fabric keeps kids comfortable during play or sleep - • **Durable & Long-Lasting:** Shrinkage-controlled fabric maintains shape wash after wash - • **Elastic Comfort Waistband:** Flexible waistband ensures all-day comfort and perfect fit - • **Ultimate Warmth, Zero Bulk:** Snug fit with thermal knit locks in heat without adding layers ## Overview Rocky Thermal Underwear for Boys is a premium 2-piece base layer set crafted from a soft, durable 55% cotton and 45% polyester blend. Designed with moisture-wicking microfibers and thermal knit technology, it provides superior warmth and comfort without bulk. Featuring an elastic waistband and shrinkage-controlled fabric, this set is perfect for cold weather activities, sleep, or everyday wear, ensuring lasting fit and cozy protection in freezing temperatures. ## Description Cold weather is fun in these Rocky Thermal Undies . Keeping warm changes everything. Perfect as extra-light gear for a ski trip or snow day, this thermal 2 piece set is high quality underwear for anything from sleeping or lounging around to athletic and sport activities. About this Product 2 piece set: 1 long sleeve top + 1 full length bottom Double layer long knit cuffs. 55% Cotton & 45% Polyester Elastic waistband Moisture wicking Full cut comfortable fit Ultra Soft Warmth Shrinkage controlled for lasting size and shape Thermal knit retains body heat to keep your child warm and comfy. Measurements Size XS - 4/5 32-41lbs 22 in waist Size Small- 6/6x 42-59 lbs 23 in waist Size Medium- 7/8 60-73lbs 24 in waist Size Large- 10/12 74-95 lbs 25-26 in waist Size XLarge 14/16- 96-119 lbs 27-28 in waist Winters can get rough and cold. These thermal long johns will help your little boy make it through. They are made of a silky soft knit. They fit snug enough that there is no bulkiness showing when worn under clothes.They are also wonderful to sleep in. These sets will continue warming you even after being laundered many times. These Rocky Smooth Knit Thermals are well designed for wear under your clothes OR alone. The waist of the pants are elastic for a comfortable snug fit. These light-weight thermal pants make all the difference in the world. Review: Very pleased, good purchase. - These are a lot like the cotton fitted pjs my kids like, but they are just a smidge thicker. I turned the sleeve inside out in my picture to show the material. I personally think they run true to size but if they lean either way it would be small. My son is a very skinny/small size 10 so the M is a little short on him and the L is a little loose in the waistband. Got the white ones for my son to wear Under his thin storm trooper Halloween costume. He likes them a lot and we are contemplating get a couple more pairs to wear as pjs. These are also going to be super convenient to wear under his clothes on snowy days. I’m completely satisfied with my purchase! Review: Poor quality - Worst material and very bad stiches ## Features - 2 PIECE SET: These Rocky thermals are designed for comfort with an elastic waistband and smooth knit moisture wicking microfibers. They are stretchy comfortable. - WONDERFULY WARM: These are perfect for use underneath clothing or for a day out, or they can be worn as comfy pajamas on cold, chilly nights. - PREMIUM GRADE FABRICS: Made from the perfect blend of comfort, warmth, elasticity, and moisture protection. - BASE LAYERS: When going out to jog, run, bike or cycle in the cold, use this set under your clothing to keep warm and cozy in freezing cold climates or bad weather. - PREMIUM GRADE FABRICS: Made from 55% Cotton 45% Polyester, these have the perfect blend of comfort, warmth, elasticity, and moisture protection. ## Technical Specifications | Specification | Value | |---------------|-------| | ASIN | B07CV1GJQ6 | | Apparel Closure Type | Pull On | | Brand Name | Rocky | | Collection | Winter | | Colour | Black | | Country Of Origin | USA | | Customer Reviews | 4.4 out of 5 stars 1,342 Reviews | | Fabric Type | 55% Cotton and 45% Ultra-Soft Polyester | | Material type | Polycotton | | Neck Style | Crew Neck | | Pattern | Solid | | Size | 2XS | | Sleeve Type | Long Sleeve | | UPC | 810829030054 | ## Images ![Rocky Thermal Underwear for Boys Cotton Knit Thermals Kids Base Layer Long John Pajamas Set - Image 1](https://m.media-amazon.com/images/I/71ewkSjsisL.jpg) ## Available Options This product comes in different **Color, Size** options. ## Customer Reviews ### ⭐⭐⭐⭐⭐ Very pleased, good purchase. *by D***G on 16 October 2020* These are a lot like the cotton fitted pjs my kids like, but they are just a smidge thicker. I turned the sleeve inside out in my picture to show the material. I personally think they run true to size but if they lean either way it would be small. My son is a very skinny/small size 10 so the M is a little short on him and the L is a little loose in the waistband. Got the white ones for my son to wear Under his thin storm trooper Halloween costume. He likes them a lot and we are contemplating get a couple more pairs to wear as pjs. These are also going to be super convenient to wear under his clothes on snowy days. I’m completely satisfied with my purchase! ### ⭐⭐ Poor quality *by S***I on 26 March 2021* Worst material and very bad stiches ### ⭐⭐⭐⭐⭐ Great price, great set! *by Q***S on 28 October 2020* This set was perfect for our son's costume this year. After reading some reviews, I ordered a size up (Medium) for our boy who normally wears a Small 5/6T. I wanted it a little lose not snug fit. It fits nicely in the waist and length on our tall ,lean boy. The material is good quality, color was bright and item just as described. Our son said is soft and comfy. Material is even softer after washing. Would definitely recommend for warm under clothing wear or pajamas! --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.jp/products/788762167-rocky-thermal-underwear-for-boys-cotton-knit-thermals-kids-base](https://www.desertcart.jp/products/788762167-rocky-thermal-underwear-for-boys-cotton-knit-thermals-kids-base) --- *Product available on Desertcart Japan* *Store origin: JP* *Last updated: 2026-10-18*