The chain lock is good combination of resistibility, weight and compact folding size. 

Features:
PORTABILITY: With approx 6cm side length folding size and included bike lock holder, you can take the lock with you or fix the lock to your bike easily.
ANTI-THEFT: Aircraft-grade alloy steel material and secure drilling & prying-resistant lock cylinder, grade 12 anti-theft standard.
MULTIDUTY: 16-joint bars, can lock several bikes together and also motorbike and electromobile.

Specifications:
Type: Bike chain lock 
Material: Alloy steel
Color: Black
Unfold Perimeter: 640mm
Thickness: 5mm
Lock Weight: 525g / 1.158lb
Folding Size: 6.1 * 6.1 * 5.6cm / 2.4 * 2.4 * 2.2in
Package Weight: 649g / 1.43lb
Package Size: 14 * 7.8 * 7.2cm / 5.5 * 3.0 * 2.8in

Package List:
1 * Bike Lock 
1 * Lock Holder
1 * L Wrench
2 * Lock Key
2 * Lock Holder Nut