These high quality solid rubber wheels go by many names in the caster industry. CasterHQ's Solid Rubber Wheels contain a thick solid soft rubber tire on a heavy industrial style plastic core. This tire is a great alternative to air filled tires since it they cannot lose air. Solid Rubber wheels help absorb shock and reduce vibrations caused by uneven grounds. These wheels perform great in grass, fields, and concrete type surfaces but are not the best if used on loose gravel or soft sand. The weight capacity is much stronger than that of a pneumatic wheel but the foot-print is slightly less wide. This wheel will last much longer than a standard pneumatic or hand truck tire and require little to no maintenance. Questions? Call us at 844-439-4335 or email us here.