Gawaarida (Bolsters) leexashada (boolayaasha) waxaa lagu qalabeeyay bililiqo biyo ah si ay si toos ah ula socdaan isteerinka isteerinka modular iyo cagaf-cagaf. Marka uu rogrogo dhaqdhaqaajiha hore, cadaadiska hawoorikada ee ka imanaya leexinta hore ayaa loo gudbin doonaa gadaal gadaal, ka dib dhululubada isteerinka ayaa jiidi doonta ama ku riixi doonta ganaax iyada oo loo marayo usha xadhigga si loo xaqiijiyo isteerinka isku mar ah. Waxaan bixinaa noocyo kala duwan oo leexsan (xoojiye) si loogu xiro Nicolas MDED, GOLDHOFER THP/SL, Scheuerle InterCombi, Commetto series SPMT, Scheuerle SPMT iyo Goldhofer PST SPMT. Gawaarida gaarka ah (boolayaasha) waa la heli karaa waxaanan soo saari karnaa rogrogmi kara (xoojiye) si ay ugu habboonaadaan trailer-kaaga qaabaysan ee hadda jira.