2-stage foams for 1.55" wheels and 4.19" RC crawler tires. They are two stage foams, outside is open cell and inside is closed memory cell. These are the stock foams for the 1.55 HUSTLER MC1 4.19 tire.
Specification:
Outer Firmness: Medium
Inner Firmness: Medium
Size:
Open foam: 103.0mm x 35mm
Close foam: 71.0mm x 29mm
Include:
2x 4.19" 1.55 2-Stage Foam Insert
Product total weight: 30.00 grams
Package size: 11.00 x 21.00 x 4.00cm
Factory description: Boom Racing 1.55 Dual 2-Stage Open/Close Cell Foams Rock Crawling Inserts for 4.19x1.38 RC Crawler Tires (2)