This is the Du-Bro 300TL 3in Treaded L/Weight Wheel 76mm (2)

DU-BRO^¬Æ Treaded Lightweight wheels feature a foam interior yet have a tough and rugged exterior skin for durability. Excellent for paved runways! 1 pair/pkg.

Features:

• Lightweight
• Shock absorbing
• Fuel resistant
• Built extremely tough

These also have many more applications in school projects and various crafts.

Cat. # - Diameter	Axle Dia.	Weight	Width
175TL - 1.75" (44.45 mm)	1/8" (3 mm)	12.8grams/wheel	0.675" (17 mm)
200TL - 2.00" (50.8 mm)	1/8" (3 mm)	16grams/wheel	0.710" (18 mm)
225TL - 2.25" (57.15 mm)	5/32" (4 mm)	25.5grams/wheel	0.780" (20 mm)
250TL - 2.50" (63.5 mm)	5/32" (4 mm)	29.4grams/wheel	0.820" (21 mm)
275TL - 2.75" (69.85 mm)	5/32" (4 mm)	35grams/wheel	0.925" (24 mm)
300TL - 3.00" (76.2 mm)	5/32" (4 mm)	42grams/wheel	1.000" (25 mm)
325TL - 3.25" (82.55 mm)	5/32" (4 mm)	50grams/wheel	1.110" (28mm)
350TL - 3.50" (88.9 mm)	5/32" (4 mm)	61grams/wheel	1.250" (32mm)