Although the product page mentions compatibility with 2S HV LiPo systems up to 8

The PowerHobby 2S 4800mAh 7

Compatible with many RC models requiring an 11

allowing them to rotate freely while transferring driving and braking forces

Material: Nylon Composite

Traxxas 10968-BLUE Blue Aluminum XL GT-Maxx Rear Shock Bodies (2) f8e-truggy Although the product page mentionsTraxxas 10968 BLUE Blue Aluminum XL GT Maxx Rear Shock Bodies (2) Upgrade your rear shocks with this genuine Traxxas set of two aluminum XL GT Maxx shock bodies in blue. Aluminum construction resists wear and dent better than stock plastic shock bodies for a more durable, better looking suspension setup. Genuine Traxxas option part XL GT Maxx rear shock bodies, set of 2 Aluminum construction, blue finish Direct fit installation