Imao’s pulleys are available from a wide variety of materials and sizes.

CTR, CTRS: Crown Pulley
・ Crown pulley for keeping belts from slipping out
・ Available from polyamide or steel body
Use with PID Idler Pins.

CTR
・ Glass-fiber reinforced polyamide body for high wear resistance
・ Stable rotation with moulded-in ball bearing
・ Applicable to 20 - 70 mm belts
・ For 10mm, 15mm and 20mm diameter spindle
Materials:
Pulley body: Glass-fiber reinforced polyamide plastic, Black color
Bearing: Steel

CTRS
・ Steel body for high wear resistance
・ Stable rotation with ball bearing
・ Applicable to 15 - 60mm belts
・ For 10mm, 15mm and 20mm diameter spindle
Materials:
Pulley body: S45C Steel, Electroless nickel plated finish
Bearing and Retaining Ring: Steel

Datasheet: https://www.imao.co.jp/files/on-cat/pdf/en/ctr_ctrs-e.pdf

Parameter Name	Parameter Value
Type	roller
Applications	belt belt tension
Other characteristics	metal bearing plastic
Pitch diameter	Max.: 64 mm (2.52 in)Min.: 34 mm (1.34 in)
Outside Diameter	Max.: 64 mm (2.52 in)Min.: 34 mm (1.34 in)
Hub diameter	Max.: 20 mm (0.79 in)Min.: 10 mm (0.39 in)
Width (mm)	20 - 70