uxcell 8mm Thread Stem 2 Inch Dia Double Wheel Brake Chair Swivel Caster 4pcs Main Material: Plastic, Metal; Package Content: 4pcs x Thread Stem Caster Wheels; Product Name: Thread Stem Caster Wheel Weight: 309g; Features: Twin Wheel; Main Color: Black,Silver Tone Overall Size: 7 x 4.5 x 7.5 cm/ 2.4" x 1.8" x 2.95" (L*W*H); Wheel Size: Each: 5 x 1.2cm/ 2" x 0.5"(D*T); Threaded Stem Size: 8 x 15mm/ 0.3" x 0.6"(D*L) Wheel Dia(a): 5 cm/2"; Total Length(b): 7.5 cm/2.95" Threaded Dia(c): 8 mm/0.3"; Threaded Length (d): 15 mm/0.6"