Accept No ImitationThis durable, functional and comfortable backpack is proven to reduce the incidence and severity of neck and back pain associated with the carriage of heavy loads. Spartan's unique multi-purpose CHIROPAK II is the only junior/senior school bag in Australia developed with and endorsed by the Australian Chiropractors Association. SMALLW 30cm x D 18cm x H 40cm21 litres plus pocket (1.10kg) MEDIUMW 32cm x D 19cm x H 46cm28 litres plus pocket (1.24kg) LARGEW 34cm x D 19cm x H 50cm32 litres plus pocket (1.34kg) EXTRA LARGEW 35cm x D 20cm x H 54cm38 litres plus pocket (1.44kg) ACA Member - Buy here ~end short~ The ACA is a national organisation representing chiropractors in Australia. The ACA promotes the highest standards of patient care and is guided by a strict code of ethics ensuring everyone can have confidence in an ACA chiropractor. The committee members are highly experienced chiropractors who evaluate and make recommendations for the endorsement of products by ACA. Endorsement by ACA indicates that the sample products exhibit good orthopaedic and ergonomic design. The ACA together with Spartan and Macquarie University (NSW), joined forces to research and develop the Chiropak. ~end long~ 420 Denier Nylon, 1000 Denier base Reversed zipsPadded back panel for extra spinal protectionSternum & side compression strapsMouldable internal spinal board for custom fit & to assist load distributionPadded laptop pocketContoured adjustable shoulder strapsMesh side drink bottle holderBlack pick up loopUnique multi fit sliding waist belt mechanism - Adjustable & padded waist beltFront accessory pocket & two double zip main compartments (M, L & XL only)Front accessory pocket & one double zip compartment (Small only) ~end features~ SMALLW 30cm x D 18cm x H 40cm21 litres plus pocket (1.10kg) MEDIUMW 32cm x D 19cm x H 46cm28 litres plus pocket (1.24kg) LARGEW 34cm x D 19cm x H 50cm32 litres plus pocket (1.34kg) EXTRA LARGEW 35cm x D 20cm x H 54cm38 litres plus pocket (1.44kg)