Rim Specifications:
Brand: Rigida - Ryde
Model: X-Plorer
Color: Silver
Size (Inch/MM):  20" / 406
External width (MM): 24
Internal width (MM): 19
Weight (GR): 401
Material: Aluminium
Single-walled / Double-walled: Double-walled
Single eyelets / Double eyelets: No eyelets
Number of spoke holes: 36
Spoke nipple size: 13
Brake surface present: Yes

Data for spoke length calculations using the Sapim spoke size calculator:

Internal diameter of the rim (MM *Not ERD*): 366

Rim thickness (MM): 2

Number of spokes in the wheel: 36

Number of crossings gear side: of your choice

Number of crossing non-gear side: of your choice

Link to spoke calculator: www.sapim.be/spoke-calculator