Rubber-Cal Elephant Bark Black 1/4 in. T x 48 in. W x 120 in. L Rubber Flooring (40 sq. ft.) 03_101_WAB_10 - The Home Depot
Costco (in Canada at least) has these sweet rubber mats that remind me of the gym. Way cheaper than Amazon since they are heavy as heck! It's flat on the other side :
RUBBER ROLL GYM FLOORING - MGR Canada
Rubber Flooring Rolls 1/4 Inch Regrind Pacific
Rubber-Cal "Recycled Flooring" 1/4 in. x 4 ft. x 5 ft. - Black Rubber Mats - Walmart.com
Rubber Flooring Rolls - Rubber Flooring Direct
Rubber - Flooring - The Home Depot
IncStores 1/4" Thick Tough Rubber Flooring Roll | Flexible Recycled Rubber Gym Floor Mats for Home Gym | Heavy Duty Rubber Mat for Home Gyms, Sheds, Horse Stall Mat or Trailer | 4'x10' | Black : Amazon.ca: Tools & Home Improvement
Rubber-Cal "Recycled Flooring" 1/4 in. x 4 ft. x 4 ft. - Black Rubber Mats - 48 x 48 - On Sale - Bed Bath & Beyond - 8247115
Rubber Garage Flooring Buying Guide
Rubber-Cal "Ramp-Cleat" Non-Slip Outdoor Rubber Mats - 1/8 inches x 3 feet x 4 feet Floor Mat - Walmart.com
IncStores 1/4" Thick Tough Rubber Flooring Roll | Flexible Recycled Rubber Gym Floor Mats for
Best Gym Floor Over Carpet for Home - StayLock Tiles
1/4" (6mm) Commercial Rolled Rubber Flooring – Pro Sports Floors