Non-slip clamp 25.4mm is suitable for Brompton bicycles. 
 
S-type, R-type and M-type are available.
S-type is 580mm long (genuine S-handle is 520mm) so you can adjust length as you like. Requesting length when you order is free of charge.
 
S-type (580mm) 118g
R-type (520mm) 128g
M-type (520mm) 138g
*It may vary slightly.
Color is gloss only.
 
Upper height M-type  95mm
Upper height R-type  45mm